Wearable devices with fluidic mechanisms

ABSTRACT

A wearable device for providing haptic stimulations is provided. The wearable device includes: (i) a wearable structure attachable to a portion of a user&#39;s body; (ii) a plurality of bladders, integrated with the wearable structure, configured to expand and contract according to fluid pressure within each bladder, where each bladder of the plurality of bladders delivers a haptic stimulation to the user wearing the wearable structure when the bladder expands a threshold amount; and (iii) at least one conduit configured to transport a fluid from a fluid source to one or more bladders of the plurality of bladders, where the fluid from the fluid source increases the fluid pressure within at least the one or more bladders. The haptic stimulation experienced by the user can correspond to media presented to the user by an artificial-reality system.

TECHNICAL FIELD

This application relates generally to haptic stimulation, includingcreating haptic stimulations on users of virtual-reality,augmented-reality, and/or mixed-reality devices.

BACKGROUND

Virtual-reality and augmented-reality devices have wide applications invarious fields, including engineering design, medical surgery practice,military simulated practice, and video gaming. Haptic or kinestheticstimulations recreate the sense of touch by applying forces, vibrations,and/or motions to a user, and are frequently implemented withvirtual-reality and augmented-reality devices. In certain applications,haptic stimulations are desired at locations where dexterity and motionof the user cannot be constrained. Conventional haptic feedback creatingdevices, however, are cumbersome and therefore detract from the userexperience.

SUMMARY

Accordingly, there is a need for devices and systems that can createhaptic stimulations on a user without constraining dexterity and motionof the user. One solution is a wearable device that includes novelhaptic mechanisms. The haptic mechanism includes one or more inflatablebladders that are configured to expand and contract according to fluidpressure within each bladder. Each bladder is made from flexible,durable materials that do not encumber the user but are still able tocreate adequate haptic stimulations. Further, the bladders are airtightso that a pressure inside the bladders can be varied to create varioushaptic stimulations (e.g., a bladder can transition rapidly betweenunpressurized and pressurized states, or vice versa). By changing thepressure, a respective bladder can go from being unpressurized andunnoticed, to being pressurized, and it is this transition that createsthe haptic stimulations felt by the user (e.g., the bladder pressesand/or vibrates against the user's body). Importantly, the hapticstimulations felt by the user can correspond to media presented to theuser by an artificial-reality system (e.g., virtual-reality oraugmented-reality devices). In some embodiments, the inflatable bladderscan also be used to improve a wearable devices coupling (e.g., fit) to auser.

(A1) In some embodiments, the solution explained above can beimplemented on a wearable device that includes: (i) a wearable structureattachable to a portion of a user's body, (ii) a plurality of bladders,integrated with the wearable structure, configured to expand andcontract according to fluid pressure within each bladder, and (iii) atleast one conduit configured to transport a fluid from a source to oneor more bladders of the plurality of bladders, where the fluid from thesource increases the fluid pressure within the one or more bladders. Insome embodiments, each bladder of the plurality of bladders delivers(e.g., imparts) a haptic stimulation to the user wearing the wearablestructure when the bladder expands a threshold amount (and/or vibratesby expanding and contracting at a threshold frequency, such as at least5 Hz),

(A2) In accordance with some embodiments, a method is provided. Themethod is performed by the wearable device of (A1). The method includesreceiving an instruction from a computer system (e.g., from the computersystem 130 in FIG. 1) to change fluid pressure in one or more firstbladders of the plurality of bladders. The instruction from the computersystem corresponds to media presented to the user by the computersystem. The method further includes, in response to receiving theinstruction, activating a pressure source to change the fluid pressurein the one or more first bladders according to the instruction. In someembodiments, each of the one or more first bladders delivers (e.g.,imparts) a haptic stimulation to the user wearing the wearable structurewhen each bladder expands a threshold amount (and/or vibrates at athreshold frequency). To further illustrate, the wearable device of (A1)can be in communication with a computer system (e.g., anaugmented-reality device and/or a virtual-reality device, such as thedevices described in FIGS. 10 and 11), and the wearable device canstimulate the body based on an instruction from the computer system. Asan example, the computer system may display media content to a user(e.g., via a head-mounted display), and the computer system may alsoinstruct the wearable device to create haptic stimulations thatcorrespond to the media content displayed to the user and/or otherinformation collected by the wearable device (e.g., via sensors includedwith the wearable device) and/or the head-mounted display. In someembodiments, the computer system activates the pressure source insteadof the wearable device.

(A3) In some embodiments of any of A1 or A2, a respective bladderincludes: (i) a first bellows coupled to the wearable structure, and(ii) a second bellows, positioned on top of the first bellows,configured to contact the user wearing the wearable structure. Moreover,first and second openings defined by the first bellows and secondbellows, respectively, create a passage that fluidically connects thefirst bellows with the second bellows.

(A4) In some embodiments of A3, the first bellows includes opposingfirst and second surfaces, whereby: (i) the first surface defines thefirst opening and is coupled to the second bellows, and (ii) the secondsurface defines a third opening and is coupled to the wearablestructure. Moreover, the fluid from the at least one conduit enters thefirst bellows at the third opening, and the fluid enters the secondbellows, from the first bellows, via the passage.

(A5) In some embodiments of any of A1-A4, the haptic stimulationexperienced by the user corresponds to media presented to the user by anartificial-reality system. The computer system mentioned in (A2) may bepart of the artificial-reality system.

(A6) In some embodiments of A5, the wearable device further includes acommunication interface in communication with the artificial-realitysystem. The communication interface receives instructions from theartificial-reality system to create the haptic stimulation.

(A7) In some embodiments of A6, the artificial-reality system is avirtual-reality or augmented-reality system, and the media presented tothe user by the artificial-reality system includes visual mediadisplayed on one or more displays of the virtual-reality oraugmented-reality system.

(A8) In some embodiments of any of A1-A7, the wearable device furtherincludes one or more sensors, integrated with the wearable structure,configured to monitor a state of a respective bladder of the pluralityof bladders.

(A9) In some embodiments of A8, the one or more sensors are furtherconfigured to provide sensor data to a controller based on the monitoredstate of the respective bladder. In some embodiments, the controller ispart of the wearable device, while in other embodiments, the controlleris part of another device (e.g., the computer system 130).

(A10) In some embodiments of A9, the sensor data includes one or moreof: (i) measurements of the bladder's expansion, (ii) measurements ofthe bladder's contraction, and (iii) measurements of the fluid pressurewithin the bladder.

(A11) In some embodiments of any of A9-A10, when the respective bladderis in an inflated state (i.e., pressurized): (i) the one or more sensorsare configured to detect depression of the respective bladder, and (ii)the sensor data provided to the controller indicates the depression ofthe respective bladder.

(A12) In some embodiments of any of A1-A11, the haptic stimulationexperienced by the user is a vibration stimulation or a pressurestimulation.

(A13) In some embodiments of any of A1-A12, two or more of the pluralityof bladders are configured to expand simultaneously.

(A14) In some embodiments of any of A1-A13, two or more of the pluralityof bladders are configured to expand sequentially.

(A15) In some embodiments of any of A1-A14, the at least one conduit isfurther configured to transport the fluid from the source to two or moreof the plurality of bladders (e.g., to each of the plurality ofbladders).

(A16) In some embodiments of any of A1-A14, the wearable device furtherincludes one or more additional conduits. Each additional conduit isconfigured to transport a fluid from the source to one or moreadditional bladders of the plurality of bladders. In some embodiments,each bladder is coupled with a distinct conduit of the one or moreadditional conduits.

(A17) In some embodiments of A16, the source includes a manifoldswitchably coupled to the at least one conduit and the one or moreadditional conduits.

(A18) In some embodiments of any of A1-A17, the wearable device furtherincludes the source.

(A19) In some embodiments of any of A1-A18, the plurality of bladdersforms a one-dimensional array of bladders along a length of the wearablestructure.

(A20) In some embodiments of any of A1-A19, one or more bladders of theplurality of bladders are selectively expanded to improve coupling(e.g., fit, snugness) of the wearable device with the user's body.

(A21) In some embodiments of A20, the wearable device further includesone or more sensors. Moreover, coupling (e.g., fit) of the wearabledevice with the user's body is evaluated according to sensor datagenerated by the one or more sensors.

(A22) In another aspect, a system is provided that includes a computersystem, a fluid source in communication with the computing device, and awearable device in communication with the computing device. The systemis configured to perform any of A1-A19. An alternative system includes awearable device, a source in communication with the wearable device, anda computing device in communication with the wearable device. Thealternative system is configured to perform any of A1-A21.

(A23) In yet another aspect, one or more wearable devices are providedand the one or more wearable devices include means for performing anyone of A1-A21.

(A24) In still another aspect, a non-transitory computer-readablestorage medium is provided (e.g., as a memory device, such as externalor internal storage, that is in communication with a wearable device).The non-transitory computer-readable storage medium stores executableinstructions that, when executed by a wearable device with one or moreprocessors/cores, cause the wearable device to perform any one ofA1-A21.

(B1) In accordance with some embodiments, a method is provided that isused to process a user input. The method is performed at a wearabledevice, attached to a user, that includes (i) an inflatable bladder and(ii) a sensor integrated with the inflatable bladder. The methodincludes instructing a pressure source to transition the inflatablebladder from an unpressurized state to a pressurized state. Theinflatable bladder is associated with a function when transitioned tothe pressurized state. The method also includes, while the inflatablebladder is in the pressurized state: (i) detecting, by the sensor,depression of the inflatable bladder, and (ii) generating, by thesensor, sensor data based on the detecting. The method also includes, inresponse to detecting the depression of the inflatable bladder: (i)determining whether a magnitude (or other characteristics) of thedepression satisfies a touch threshold, based on the sensor data, and(ii) in accordance with a determination that the magnitude of thedepression satisfies the touch threshold, executing the function.

(B2) In some embodiments of the method of B1, depression of theinflatable bladder, while the inflatable bladder is in the pressurizedstate, provides tactile feedback to the user (e.g., depression of theinflatable bladder resembles depression of a physical button).

(B3) In some embodiments of the method of any of B1 or B2, the wearabledevice includes a display, and executing the function includes modifyinga user interface displayed on the display.

(B4) In some embodiments of the method of any of B1-B3, while theinflatable bladder is in the pressurized state, the method generates areminder of an event. Moreover, executing the function includesacknowledging the event. For example, the wearable device may generatean audio reminder, and the executing the function involves silencing theaudio reminder.

(B5) In some embodiments of the method of any of B1-B4, the wearabledevice is in communication with another electronic device, and executingthe function includes sending an instruction to the other electronicdevice according to the function.

(B6) In some embodiments of the method of B5, the other electronicdevice is an artificial-reality system that includes a head-mounteddisplay, and sending the instruction to the other electronic devicecauses media displayed on the head-mounted display to change. Forexample, an alert (or some other message) may be displayed on thehead-mounted display, and the user may use the wearable device toacknowledge the alert (e.g., select an affordance displayed in themessage).

(B7) In some embodiments of the method of any of B1-B6, the sensor dataincludes one or more of: (i) measurements of the bladder's expansion,(ii) measurements of the bladder's contraction, and (iii) measurementsof the fluid pressure within the bladder.

(B8) In some embodiments of the method of any of B1-B7, instructing thepressure source to transition the inflatable bladder from theunpressurized state to the pressurized state causes the pressure sourceto add fluid to the inflatable bladder to increase fluid pressure withinthe bladder.

(B9) In some embodiments of the method of any of B1-B8, the wearabledevice has the structure of or is configured to perform any of A1-A19.

(B10) In yet another aspect, a wearable device is provided and thewearable device includes means for performing the method described inany one of B1-B9.

(B11) In another aspect, a wearable device includes (i) an inflatablebladder and (ii) a sensor integrated with the inflatable bladder isprovided. In some embodiments, the wearable device is in communicationwith one or more processors and memory storing one or more programswhich, when executed by the one or more processors, cause the wearabledevice to perform the method described in any one of B1-B9.

(B12) In still another aspect, a non-transitory computer-readablestorage medium is provided (e.g., as a memory device, such as externalor internal storage, that is in communication with a wearable device).The non-transitory computer-readable storage medium stores executableinstructions that, when executed by a wearable device with one or moreprocessors/cores, cause the wearable device to perform the methoddescribed in any one of B1-B9.

(B13) In still another aspect, a system is provided. The system includesa computer system, a fluid source in communication with the computingdevice, and a wearable device in communication with the computingdevice. The system is configured to perform any of B1-B9. An alternativesystem includes a wearable device, a source in communication with thewearable device, and a computing device in communication with thewearable device. The alternative system is configured to perform any ofB1-B9.

The devices, methods, and systems described herein provide benefitsincluding but not limited to: (i) stimulating areas of the body thatcorrespond to media content and sensor data, (ii) the wearable devicedoes not encumber free movement of a user's body, (iii) multiplewearable devices can be used simultaneously, and (iv) the wearabledevice can be turned into an input device dynamically.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the various described embodiments,reference should be made to the Description of Embodiments below, inconjunction with the following drawings in which like reference numeralsrefer to corresponding parts throughout the figures and specification.

FIG. 1 is a block diagram illustrating an example haptics system, inaccordance with various embodiments.

FIG. 2A is a schematic of an example haptics system in accordance withsome embodiments.

FIG. 2B is another schematic of an example haptics system in accordancewith some embodiments.

FIGS. 3A and 3B show various views of a simplified wearable device inaccordance with some embodiments.

FIG. 4 shows a cross-sectional view of the simplified wearable device(taken along line A-A¹ in FIG. 3A).

FIGS. 5A-5C show cross-sectional views of a representative bladder inaccordance with some embodiments.

FIGS. 6A and 6B show examples of a representative wearable device indifferent states in accordance with some embodiments.

FIG. 6C shows an example of a representative wearable device attached toa user.

FIG. 6D shows a graph illustrating forces applied to a user based on apressure and distance.

FIGS. 7A-7H illustrate a process of fabricating an example wearabledevice in accordance with some embodiments.

FIG. 8 is a flow diagram illustrating a method of creating hapticstimulations in accordance with some embodiments.

FIG. 9 illustrates an embodiment of an artificial-reality device.

FIG. 10 illustrates an embodiment of an augmented-reality headset and acorresponding neckband.

FIG. 11 illustrates an embodiment of a virtual-reality headset.

FIG. 12 illustrates recorded normal force under bladders duringdifferent haptic cues applied to a user's wrist.

DESCRIPTION OF EMBODIMENTS

Reference will now be made to embodiments, examples of which areillustrated in the accompanying drawings. In the following description,numerous specific details are set forth in order to provide anunderstanding of the various described embodiments. However, it will beapparent to one of ordinary skill in the art that the various describedembodiments may be practiced without these specific details. In otherinstances, well-known methods, procedures, components, circuits, andnetworks have not been described in detail so as not to unnecessarilyobscure aspects of the embodiments.

It will also be understood that, although the terms first, second, etc.are, in some instances, used herein to describe various elements, theseelements should not be limited by these terms. These terms are used onlyto distinguish one element from another. For example, a first bladdercould be termed a second bladder, and, similarly, a second bladder couldbe termed a first bladder, without departing from the scope of thevarious described embodiments. The first bladder and the second bladderare both bladders, but they are not the same bladder.

The terminology used in the description of the various describedembodiments herein is for the purpose of describing particularembodiments only and is not intended to be limiting. As used in thedescription of the various described embodiments and the appendedclaims, the singular forms “a,” “an,” and “the” are intended to includethe plural forms as well, unless the context clearly indicatesotherwise. It will also be understood that the term “and/or” as usedherein refers to and encompasses any and all possible combinations ofone or more of the associated listed items. It will be furtherunderstood that the terms “includes,” “including,” “comprises,” and/or“comprising,” when used in this specification, specify the presence ofstated features, steps, operations, elements, and/or components, but donot preclude the presence or addition of one or more other features,steps, operations, elements, components, and/or groups thereof.

As used herein, the term “if” means “when” or “upon” or “in response todetermining” or “in response to detecting” or “in accordance with adetermination that,” depending on the context. Similarly, the phrase “ifit is determined” or “if [a stated condition or event] is detected”means “upon determining” or “in response to determining” or “upondetecting [the stated condition or event]” or “in response to detecting[the stated condition or event]” or “in accordance with a determinationthat [a stated condition or event] is detected,” depending on thecontext.

As used herein, the term “exemplary” is used in the sense of “serving asan example, instance, or illustration” and not in the sense of“representing the best of its kind.”

FIG. 1 is a block diagram illustrating a virtual-reality (and/oraugmented-reality or mixed-reality) system 100 in accordance withvarious embodiments. While some example features are illustrated,various other features have not been illustrated for the sake of brevityand so as not to obscure pertinent aspects of the example embodimentsdisclosed herein. To that end, as a non-limiting example, the system 100includes one or more wearable devices 120 (sometimes referred to as“haptic devices,” “wearable apparatuses,” or simply “apparatuses”),which are used in conjunction with a computer system 130 (sometimesreferred to a “remote computer system”) and a head-mounted display 110.In some embodiments, the system 100 provides the functionality of avirtual-reality device with haptic feedback, an augmented-reality devicewith haptic feedback, a mixed-reality device with haptic feedback, or acombination thereof.

The head-mounted display 110 presents media to a user. Examples of mediapresented by the head-mounted display 110 include images, video, audio,or some combination thereof. In some embodiments, audio is presented viaan external device (e.g., speakers and/or headphones), which receivesaudio information from the head-mounted display 110, the computer system130, or both, and presents audio data based on the audio information.

The head-mounted display 110 includes an electronic display 112, sensors114, and a communication interface 116. The electronic display 112displays images to the user in accordance with data received from thecomputer system 130. In various embodiments, the electronic display 112comprises a single electronic display 112 or multiple electronicdisplays 112 (e.g., one display for each eye of a user).

The sensors 114 include one or more hardware devices that detect spatialand motion information about the head-mounted display 110. Spatial andmotion information can include information about the position,orientation, velocity, rotation, and acceleration of the head-mounteddisplay 110. For example, the sensors 114 may include one or moreinertial measurement units (IMUs) that detect rotation of the user'shead while the user is wearing the head-mounted display 110. Thisrotation information can then be used (e.g., by the engine 134) toadjust the images displayed on the electronic display 112. In someembodiments, each IMU includes one or more gyroscopes, accelerometers,and/or magnetometers to collect the spatial and motion information. Insome embodiments, the sensors 114 include one or more cameras positionedon the head-mounted display 110.

The communication interface 116 enables input and output to the computersystem 130. In some embodiments, the communication interface 116 is asingle communication channel, such as HDMI, USB, VGA, DVI, orDisplayPort. In other embodiments, the communication interface 116includes several distinct communication channels operating together orindependently. In some embodiments, the communication interface 116includes hardware capable of data communications using any of a varietyof custom or standard wireless protocols (e.g., IEEE 802.15.4, Wi-Fi,ZigBee, 6LoWPAN, Thread, Z-Wave, Bluetooth Smart, ISA100.11a,WirelessHART, or MiWi) and/or any other suitable communication protocol.The wireless and/or wired connections may be used for sending datacollected by the sensors 114 from the head-mounted display to thecomputer system 130. In such embodiments, the communication interface116 may also receive audio/visual data to be rendered on the electronicdisplay 112.

The wearable device 120 includes a wearable structure worn by the user(e.g., a glove, a shirt, wristband, pants, etc.). In some embodiments,the wearable device 120 collects information about a portion of theuser's body (e.g., the user's hand) that can be used as input forvirtual-reality applications 132 executing on the computer system 130.In the illustrated embodiment, the wearable device 120 includes a hapticfeedback mechanism 122, sensors 124, and a communication interface 126.The wearable device 120 may include additional components that are notshown in FIG. 1, such as a power source (e.g., an integrated battery, aconnection to an external power source, a container containingcompressed air, or some combination thereof), one or more processors,and memory.

The haptic feedback mechanism 122 provides haptic feedback (i.e., hapticstimulations) to a portion of the user's body (e.g., hand, wrist, arm,leg, etc.). The haptic feedback may be a vibration stimulation, apressure stimulation, or some combination thereof. To accomplish this,the haptic feedback mechanism 122 includes a plurality of inflatablebladders 204, each of which is configured to inflate and apply a forceto the portion of the user's body. Various embodiments of the hapticfeedback mechanism 122 are described with reference to FIGS. 3A-6C. Itis also noted that the haptic feedback mechanism 122 may be used toimprove coupling (e.g., fit) of the wearable device 120 to the user. Forexample, instead of (or in addition to) providing a haptic stimulation,one or more bladders 204 of the plurality of inflatable bladders 204 areinflated to varying degrees such that contact is made with the user'sbody. The contacting bladders prevent the wearable device 120 frommoving (e.g., sliding or rotating) when attached to the user's body.This embodiment is particular useful in applications where movement of awearable device is problematic, such as diving, where it is asignificant inconvenience for a diver to continually adjust positioningof a wearable device.

In some embodiments, the sensors 124 include one or more hardwaredevices that detect spatial and motion information about the wearabledevice 120. Spatial and motion information can include information aboutthe position, orientation, velocity, rotation, and acceleration of thewearable device 120 or any subdivisions of the wearable device 120, suchas fingers, fingertips, knuckles, the palm, or the wrist when thewearable device 120 is worn near the user's hand. The sensors 124 may beIMUs, as discussed above with reference to the sensors 114. The sensors124 may include one or more hardware devices that monitor a state of arespective bladder 204 of the haptic feedback mechanism 122. Sensors formonitoring a bladder's state are discussed in more detail below withreference to FIGS. 5A-5C.

The communication interface 126 enables input and output to the computersystem 130. In some embodiments, the communication interface 126 is asingle communication channel, such as USB. In other embodiments, thecommunication interface 126 includes several distinct communicationchannels operating together or independently. For example, thecommunication interface 126 may include separate communication channelsfor receiving control signals for the haptic feedback mechanism 122 andsending data from the sensors 124 to the computer system 130. The one ormore communication channels of the communication interface 126 can beimplemented as wired or wireless connections. In some embodiments, thecommunication interface 126 includes hardware capable of datacommunications using any of a variety of custom or standard wirelessprotocols (e.g., IEEE 802.15.4, Wi-Fi, ZigBee, 6LoWPAN, Thread, Z-Wave,Bluetooth Smart, ISA100.11a, WirelessHART, or MiWi), custom or standardwired protocols (e.g., Ethernet or HomePlug), and/or any other suitablecommunication protocol, including communication protocols not yetdeveloped as of the filing date of this document.

The computer system 130 is a computing device that executesvirtual-reality applications and/or augmented-reality applications toprocess input data from the sensors 114 on the head-mounted display 110and the sensors 124 on the wearable device 120. The computer system 130provides output data for (i) the electronic display 112 on thehead-mounted display 110 and (ii) the haptic feedback mechanism 122 onthe wearable device 120.

The computer system includes a communication interface 136 that enablesinput and output to other devices in the system 100. The communicationinterface 136 is similar to the communication interface 116 and thecommunication interface 126.

In some embodiments, the computer system 130 sends instructions (e.g.,the output data) to the wearable device 120. In response to receivingthe instructions, the wearable device 120 creates one or more hapticstimulations (e.g., activates one or more of the bladders 204).Alternatively, in some embodiments, the computer system 130 sendsinstructions to an external device, such as a fluid (pressure) source,and in response to receiving the instructions, the external devicecreates one or more haptic stimulations (e.g., the output data bypassesthe wearable device 120). Alternatively, in some embodiments, thecomputer system 130 sends instructions to the wearable device 120, whichin turn sends the instructions to the external device. The externaldevice then creates one or more haptic stimulations by adjusting fluidpressure in one or more of the bladders 204. Although not shown, in theembodiments that include a distinct external device, the external devicemay be connected to the head-mounted display 110, the wearable device120, and/or the computer system 130 via a wired or wireless connection.The external device may be a pneumatic device, a hydraulic device, somecombination thereof, or any other device capable of adjusting pressure.

The computer system 130 can be implemented as any kind of computingdevice, such as an integrated system-on-a-chip, a microcontroller, adesktop or laptop computer, a server computer, a tablet, a smart phoneor other mobile device. Thus, the computer system 130 includescomponents common to typical computing devices, such as a processor,random access memory, a storage device, a network interface, an I/Ointerface, and the like. The processor may be or include one or moremicroprocessors or application specific integrated circuits (ASICs). Thememory may be or include RAM, ROM, DRAM, SRAM and MRAM, and may includefirmware, such as static data or fixed instructions, BIOS, systemfunctions, configuration data, and other routines used during theoperation of the computing device and the processor. The memory alsoprovides a storage area for data and instructions associated withapplications and data handled by the processor.

The storage device provides non-volatile, bulk, or long term storage ofdata or instructions in the computing device. The storage device maytake the form of a magnetic or solid state disk, tape, CD, DVD, or otherreasonably high capacity addressable or serial storage medium. Multiplestorage devices may be provided or available to the computing device.Some of these storage devices may be external to the computing device,such as network storage or cloud-based storage. The network interfaceincludes an interface to a network and can be implemented as eitherwired or wireless interface. The I/O interface interfaces the processorto peripherals (not shown) such as, for example and depending upon thecomputing device, sensors, displays, cameras, color sensors,microphones, keyboards, and USB devices.

In the example shown in FIG. 1, the computer system 130 further includesvirtual-reality (and/or augmented-reality) applications 132 and avirtual-reality (and/or augmented-reality) engine 134. In someembodiments, the virtual-reality applications 132 and thevirtual-reality engine 134 are implemented as software modules that arestored on the storage device and executed by the processor. Someembodiments of the computer system 130 include additional or differentcomponents than those described in conjunction with FIG. 1. Similarly,the functions further described below may be distributed amongcomponents of the computer system 130 in a different manner than isdescribed here.

Each virtual-reality application 132 is a group of instructions that,when executed by a processor, generates virtual-reality content forpresentation to the user. A virtual-reality application 132 may generatevirtual-reality content in response to inputs received from the user viamovement of the head-mounted display 110 or the wearable device 120.Examples of virtual-reality applications 132 include gamingapplications, conferencing applications, and video playbackapplications.

The virtual-reality engine 134 is a software module that allowsvirtual-reality applications 132 to operate in conjunction with thehead-mounted display 110 and the wearable device 120. In someembodiments, the virtual-reality engine 134 receives information fromthe sensors 114 on the head-mounted display 110 and provides theinformation to a virtual-reality application 132. Based on the receivedinformation, the virtual-reality engine 134 determines media content toprovide to the head-mounted display 110 for presentation to the user viathe electronic display 112 and/or a type of haptic feedback to becreated by the haptic feedback mechanism 122 of the wearable device 120.For example, if the virtual-reality engine 134 receives information fromthe sensors 114 on the head-mounted display 110 indicating that the userhas looked to the left, the virtual-reality engine 134 generates contentfor the head-mounted display 110 that mirrors the user's movement in avirtual environment.

Similarly, in some embodiments, the virtual-reality engine 134 receivesinformation from the sensors 124 on the wearable device 120 and providesthe information to a virtual-reality application 132. The application132 can use the information to perform an action within the virtual (oraugmented) world of the application 132. For example, if thevirtual-reality engine 134 receives information from the sensors 124that the user has closed his fingers around a position corresponding toa coffee mug in the virtual environment and raised his hand, a simulatedhand in the virtual-reality application 132 picks up the virtual coffeemug and lifts it to a corresponding height. As noted above, theinformation received by the virtual-reality engine 134 can also includeinformation from the head-mounted display 110. For example, cameras onthe head-mounted display 110 may capture movements of the wearabledevice 120, and the application 132 can use this additional informationto perform the action within the virtual world of the application 132.

In some embodiments, the virtual-reality engine 134 provides feedback tothe user that the action was performed. The provided feedback may bevisual via the electronic display 112 in the head-mounted display 110(e.g., displaying the simulated hand as it picks up and lifts thevirtual coffee mug) and/or haptic feedback via the haptic feedbackmechanism 122 in the wearable device 120. For example, the hapticfeedback may vibrate in a certain way to simulate the sensation offiring a firearm in a virtual-reality video game. To do this, thewearable device 120 changes (either directly or indirectly) fluidpressure of one or more of bladders of the haptic feedback mechanism122. When inflated by a threshold amount (and/or inflated at a thresholdfrequency, such as at least 5 Hz), a respective bladder of the hapticfeedback mechanism 122 presses against the user's body, resulting in thehaptic feedback. The wearable device 120 is discussed in further detailbelow with reference to FIGS. 3A to 6C.

To provide some additional context, the bladders described herein areconfigured to transition between a first pressurized state and a secondpressurized state to provide haptic feedback to the user. Due to theever-changing nature of virtual and augmented reality, the bladders maybe required to transition between the two states hundreds, or perhapsthousands of times, during a single use. Thus, the bladders describedherein are durable and designed to quickly transition from state tostate (e.g., within 10 milliseconds). In the first pressurized state, arespective bladder is unpressurized (or a fluid pressure inside therespective bladder is below a threshold pressure) and does not providehaptic feedback to a portion of the wearer's body. However, once in thesecond pressurized state (e.g., the fluid pressure inside the respectivebladder reaches the threshold pressure), the respective bladder isconfigured to expand and press against the portion of the wearer's body,and in some cases, resist movement of the portion of the wearer's body.

As mentioned above, the haptic stimulations created by the wearabledevice 120 can correspond to data displayed by the head-mounted display110. The data (e.g., media content) displayed by the head-mounteddisplay 110 (e.g., via the electronic display 112) may depict the wearerwalking in a virtual world (or augmented version of the real world). Thewearable device 120 may create one or more haptic stimulations toprovide directions to the user. For example, if the wearer is to turnleft in the virtual world down a street, then the wearable device 120,if positioned on the wearer's left wrist, may vibrate in a certainmanner to alert the wearer of the needed left turn. In another example,the data (i.e., media content) displayed by the head-mounted display 110(e.g., via the electronic display 112) depicts the wearer with a bow andarrow. The wearable device 120 may create one or more hapticstimulations to mimic a feeling of the arrow being released from thebow. For example, if the wearer is holding the virtual bow in his lefthand, then the haptic stimulation may be created on the left wrist tomimic the force of the arrow being released from the bow. In view of theexamples above, the wearable device 120 is used to further immerse theuser in virtual and/or augmented reality experience such that the usernot only sees (at least in some instances) the data on the head-mounteddisplay 110, but the user may also “feel” certain aspects of thedisplayed data. Moreover, the wearable device 120 is designed to notrestrict movement of the user's appendages, until desired.

FIG. 2A is a schematic of the system 100 in accordance with someembodiments. The components in FIG. 2A are illustrated in a particulararrangement for ease of illustration and one skilled in the art willappreciate that other arrangements are possible. Moreover, while someexample features are illustrated, various other features have not beenillustrated for the sake of brevity and so as not to obscure pertinentaspects of the example implementations disclosed herein.

As a non-limiting example, the system 100 includes a plurality ofwearable devices 120-A, 120-B, . . . 120-M, each of which includes awearable structure 202 and a haptic feedback mechanism 122. Each hapticfeedback mechanism 122 includes a plurality of bladders 204, and asexplained above, the bladders 204 are configured to provide hapticstimulations to a wearer of the wearable device 120. The wearablestructure 202 of each wearable device 120 can be various articles ofclothing (e.g., gloves, socks, shirts, or pants) or other wearablestructure (e.g., watch band), and thus, the user may wear multiplewearable devices 120 that provide haptic stimulations to different partsof the body. In some embodiments, the wearable structure 202 is madefrom an elastic material, thereby allowing the wearable device 120 tofit various users. In some embodiments, a distance between adjacentbladders 204 increases from a base distance when the elastic materialstretches to accommodate (e.g., a wrist) of a particular user.

Each bladder 204 is integrated with (e.g., embedded in or coupled to)the wearable structure 202. The bladder 204 is a sealed, inflatablepocket made from a durable, puncture resistance material, such asthermoplastic polyurethane (TPU) or the like. Each bladder 204 isconfigured to expand or contract according to fluid pressure within eachbladder. Fluid as used herein can be various media, including air, aninert gas, or a liquid. In some embodiments, each bladder 204 delivers(e.g., imparts) a haptic stimulation to the user wearing the wearablestructure 202 when the bladder expands a threshold amount (i.e., a fluidpressure within the bladder reaches a threshold pressure). The thresholdamount of expansion can range from 1 mm to 15 mm. Each bladder 204 canalso deliver a haptic stimulation to the user wearing the wearablestructure 202 when the bladder expands and contracts at a thresholdfrequency (e.g., greater than approximately 5 Hz). An example method forfabricating a plurality of bladders 204 on a wearable structure 202 isprovided below in FIGS. 7A-7H. In one example, the wearable structure202 with a plurality of bladders 204 (e.g., eight bladders) attachedthereto weighs approximately 15 grams and has a width of 20 mm.

The system 100 also includes a controller 214 and a fluid source 210(e.g., a pneumatic device). In some embodiments, the controller 214 ispart of the computer system 130 (e.g., the processor of the computersystem 130). Alternatively, in some embodiments, the controller 214 ispart of the wearable device 120. The controller 214 is configured tocontrol operation of the source 210, and in turn the operation (at leastpartially) of the wearable devices 120. For example, the controller 214sends one or more signals to the source 210 to activate the source 210(e.g., turn it on and off). The one or more signals may specify adesired pressure (e.g., pounds-per-square inch) to be output by thesource 210. Additionally, the one or more signals may specify a desiredfrequency for outputting the desired pressure (e.g., 0.5 Hz to 50 Hz).The one or more signals may further specify one or more of: (i) one ormore target bladders 204 to be inflated and (ii) a pattern of inflationfor the one or more target bladders 204. The pattern of inflation maydefine a direction for inflating the one or more target bladders 204(e.g., left to right, right to left, edge to center, center to edge, orcircular) and inflation crossover between adjacent bladders of the oneor more target bladders 204 (e.g., a bladder is inflated for X-amount oftime while an adjacent bladder is inflated).

Generation of the one or more signals, and in turn the pressure outputby the source 210, may be based on information collected by the HMDsensors 114 and/or the wearable device sensors 124. For example, the oneor more signals may cause the source 210 to increase the pressure insideone or more bladders 204 of a first wearable device 120 at a first time,based on the information collected by the sensors 114 and/or the sensors124 (e.g., the user makes contact with the virtual coffee mug or fires avirtual firearm). Then, the controller 214 may send one or moreadditional signals to the source 210 that cause the source 210 tofurther increase the pressure inside the one or more bladders 204 of thefirst wearable device 120 at a second time after the first time, basedon additional information collected by the sensors 114 and/or thesensors 124 (e.g., the user grasps and lifts the virtual coffee mug).Further, the one or more signals may cause the source 210 to inflate oneor more bladders 204 in a first wearable device 120-A, while one or morebladders 204 in a second wearable device 120-B remain unchanged (or areinflated to some other pressure). Additionally, the one or more signalsmay cause the source 210 to inflate one or more bladders 204 in thefirst wearable device 120-A to a first pressure and inflate one or moreother bladders 204 in the first wearable device 120-A to a secondpressure different from the first pressure. Depending on the number ofwearable devices 120 serviced by the source 210, and the number ofbladders therein, many different inflation configurations can beachieved through the one or more signals and the examples above are notmeant to be limiting.

In some embodiments, the system 100 includes a manifold 212 between thesource 210 and the wearable devices 120. In some embodiments, themanifold 212 includes one or more valves (not shown) that fluidically(e.g., pneumatically) couple each of the haptic feedback mechanisms 122with the source 210 via tubing 208 (also referred to herein as“conduits”). In some embodiments, the tubing is ethylene propylene dienemonomer (EPDM) rubber tubing with 1/32″ inner diameter (various othertubing can also be used). In some embodiments, the manifold 212 is incommunication with the controller 214, and the controller 214 controlsthe one or more valves of the manifold 212 (e.g., the controllergenerates one or more control signals). The manifold 212 is configuredto switchably couple the source 210 with the bladders 204 of the same ordifferent wearable devices 120 based on one or more control signals fromthe controller 214. In some embodiments, instead of the manifold 212being used to fluidically couple the source 210 with the haptic feedbackmechanisms 122, the system 100 includes multiple sources 210, where eachis fluidically coupled directly with a single (or multiple) bladder(s)204. In some embodiments, the source 210 and the optional manifold 212are configured as part of one or more of the wearable devices 120 (notillustrated) while, in other embodiments, the source 210 and theoptional manifold 212 are configured as external to the wearable device120. A single source 210 may be shared by multiple wearable devices 120.

In some embodiments, the source 210 is a pneumatic device, hydraulicdevice, a pneudraulic device, or some other device capable of adding andremoving a medium from the one or more bladders 204. In other words, thediscussion herein is not limited to pneumatic devices, but for ease ofdiscussion, pneumatic devices are used as the primary example in thediscussion below.

The devices shown in FIG. 2A may be coupled via a wired connection(e.g., via busing 108). Alternatively, one or more of the devices shownin FIG. 2A may be wirelessly connected (e.g., via short-rangecommunication signals).

FIG. 2B is another schematic of the system 100 in accordance with someembodiments. While some example features are illustrated in FIG. 2B,various other features have not been illustrated for the sake of brevityand so as not to obscure pertinent aspects of the exampleimplementations disclosed herein.

FIG. 2B details components used to control fluid transfer from thesource 210 to a respective bladder 204. The components include aregulator 256 (e.g., a Kelly Pneumatics Inc. high flow pressureregulator), a fluid chamber 258, a valve 260, and a pressure sensor 262(e.g., Cynergy3 IPSU-GP100-6 pressure sensors). Accordingly, to controlactuation of the bladder 204, the regulator 256 is set to the desiredpressure (Pdes), and the output of the regulator 256 is fed to the valve260. In this example, the valve 260 is connected to a single bladder204, allowing easy alternation between Pdes and Pam, (note, in someembodiments, the valve 260 is connected to multiple bladders 204). Thearrangement shown in FIG. 2B can produce step responses on the order of10 ms using the valve 260, and analog pressure control on the order ofseconds using the regulator 256. The fluid chamber 258, while optional,eliminates a gradual pressure rise that results from the regulator 256compensating for fluid flow to the bladder 204. To do this, the fluidchamber 258 adds fluid between the regulator 256 and the valve 260 whenthe valve 260 is opened. In some embodiments, sensor measurements by thesensor 262 are recorded at greater than 1000 Hz, including the pressurebetween the valve and the bellow and the force/torque exerted by thebellow.

FIGS. 3A and 3B show various views of a representative wearable device120 in accordance with some embodiments. In particular, FIG. 3A is anisometric view of the wearable device 120 and FIG. 3B shows across-sectional view of the wearable device 120 (taken along line A-A′in FIG. 3A). As shown, the wearable device 120 includes (i) a wearablestructure 202 and (ii) multiple bladders 204-A, 204-B, . . . 204-Lintegrated with the wearable structure 202. Each bladder 204 isconfigured expand and contract according to fluid pressure within eachbladder 204. Furthermore, each bladder 204 delivers (e.g., imparts) ahaptic stimulation to the user wearing the wearable structure 202 whenthe bladder 204 expands a threshold amount (and/or vibrates at athreshold frequency). A bladder 204 is referred to below as being“activated” when the bladder 204 expands the threshold amount (and/orvibrates at a threshold frequency). Each bladder 204 can withstand over100 kPa of pressure, extend over 10 mm, and exert over 10 N of force atzero displacement.

Each bladder 204 is capable of creating multiple types of hapticstimulations (also referred to as “tactile feedback,” “haptic feedback”or “haptic cues”), including a pressure stimulation and a vibrationstimulation. The pressure stimulation is created (e.g., generated) whenthe bladder 204 expands the threshold amount, and in doing so, pressesagainst the user's body. In some embodiments, each bladder 204 iscapable of creating pressure stimulations of different magnitudes. Forexample, a first pressure stimulation (least intense) is created whenthe bladder 204 expands a first threshold amount (e.g., contact is madewith the user's body, but minimal pressure is applied to the user), asecond pressure stimulation is created when the bladder 204 expands asecond threshold amount greater than the first threshold amount (e.g.,contact is made with the user's body and significant pressure is appliedto the user), and so on. In some embodiments, the magnitude of thepressure stimulation corresponds to media presented to the user by thehead-mounted display 110.

The vibration stimulation is created by repeatedly changing the fluidpressure within the bladder 204, where the bladder 204 expands athreshold amount during each cycle. In some embodiments, each bladder204 is capable of creating vibration stimulations of differentmagnitudes and frequency. For example, a first vibration stimulation(least intense) is created when the bladder 204 expands a firstthreshold amount during each cycle (e.g., contact may or may not be madewith the user's body, but the user can nevertheless feel the vibration),a second vibration stimulation is created when the bladder 204 expands asecond threshold amount greater than the first threshold amount duringeach cycle (e.g., contact is made), and so on. Additionally, the firstvibration stimulation may have a first frequency and the secondvibration stimulation may have a second frequency, where the secondfrequency is greater that the first frequency (or vice versa). In someembodiments, the magnitude and frequency of the vibration stimulationcorresponds to media presented to the user by the head-mounted display110.

Furthermore, when two or more bladders are activated simultaneously (orsequentially), the wearable device 120 is capable of creating (e.g.,generating) various other haptic simulations, including a touchstimulation, a swipe stimulation, a pull stimulation, a pushstimulation, a rotation stimulation, a heat stimulation, a pulsatingstimulation, a local vibration stimulation, a local pressurestimulation, a uniform squeezing stimulation, and a uniform vibrationstimulation. Additionally, in some embodiments, each of the bladders 204of a respective wearable device 120 is activated simultaneously. FIG. 12illustrates recorded normal force under each bladder 204 duringdifferent haptic cues applied to a user's wrist. As shown in FIG. 12,the different haptic cues include (a) pressure increase in one bladder,(b) pressure increase in all bladders, (c) vibration in one bladder, and(d) vibration in all bladders. The measured normal forces are shown inthe small circles used to represent bladders, and the arrows indicatecommanded pressure.

In some embodiments, each bladder 204 defines an opening that is sizedto accommodate a valve (this valve is different from the manifold valvesdiscussed above). The valve is fitted into the opening so that thebladder 204 remains sealed (i.e., airtight). In some embodiments, anadhesive may be deposited around a perimeter of the opening defined bythe bladder 204 to ensure that the bladder 204 remains sealed (e.g., toensure that the valve remains fixed in the opening). Alternatively, orin addition, an adhesive may be deposited around the valve to ensurethat the bladder 204 remains sealed (e.g., to ensure that the valveremains fixed in the opening). The valve may be made from metal (e.g.,stainless steel).

The valve may be fixed to an end of a conduit 208 (e.g., tubing). Eachconduit 208 is configured to transport a fluid from the source 210 toone or more bladders (or each) of the plurality of bladders. In someembodiments, the number of conduits in less than the number of bladders204 (e.g., each conduit 208 is configured to transport fluid from thesource to two or more bladders 204). In such embodiments, one or morechannels may be used to fluidically couple adjacent (or non-adjacent)bladders to each other. In this way, fewer conduits are needed toservice each of the bladders 204. In other embodiments, the number ofconduits is equal to the number of bladders 204 (e.g., there is aone-to-one relationship between conduits 208 and bladders 204). In thisway, each bladder 204 is serviced individually by a respective conduit208. In some embodiments, the wearable device 120 includes a singleconduit 208 that is configured to transport fluid from the source to oneor more of the bladders 204 included in the wearable device 120. Inother embodiments, the wearable device 120 includes multiple conduits208, each of which is configured to transport fluid from the source toone or more of the bladders 204 included in the wearable device 120.

The orientation of the conduits 208 shown in FIG. 3B is merely oneexample orientation. In other embodiments, the conduits 208 areperpendicular to the orientation shown in FIG. 3B. For example, withreference to FIG. 6A, the conduits 208 are positioned horizontally, incontrast to their vertical orientation shown in FIG. 3B. It is alsonoted that the bladders 204 may be embedded, at least partially, withinthe wearable structure 202. The circular (e.g., disk) shape of thebladders 204-A, 204-B, . . . 204-N shown in FIG. 3A is merely oneexample bladder shape, and the bladders 204 may have different shapes,such as rectangular, triangular, or elliptical. Moreover, one or morefirst bladders 204 may have a first shape and one or more secondbladders may a second shape different from the first shape. Thedifferent shapes of the bladders may be used to suit a particularapplication (e.g., a structure of a particular wearable device mayrequire rectangular bladders), and also may be used to impart differenthaptic stimulations to the user (e.g., a rectangular-shaped bladder maybe more suitable to impart a haptic stimulation in first circumstancesand a circular-shaped bladder may be more suitable to impart a hapticstimulation in second circumstances). In those embodiments withnon-circular shaped bladders, corners of the bladders may be rounded tomake the bladders more durable and robust.

In FIGS. 3A and 3B, the multiple bladders 204-A, 204-B, . . . 204-L forma one-dimensional array of bladders along a length of the wearablestructure. Additionally, when the wearable device 120 is attached to theuser, the one-dimensional array of bladders forms a circular array ofbladders (e.g., bladders in the array are radially spaced, and in someinstances, equidistant from each other). In addition, in someembodiments, the multiple bladders 204-A, 204-B, . . . 204-L form amulti-dimensional array of bladders. For example, the multiple bladders204-A, 204-B, . . . 204-L may include at least one row of bladders(e.g., as shown in FIG. 3A) (i.e., a first dimension) and at least onecolumn of bladders (i.e., a second dimension), where the at least onecolumn of bladders includes at least two bladders. The column ofbladders can be used to increase the magnitude (and contact area) of ahaptic stimulation at a specific location. In some embodiments, thewearable device 120 includes an equal number of rows and columns ofbladders 204 (e.g., one-to-one, two-to-two, and so on). Additionalexamples of the wearable device 120 are illustrated in FIGS. 6A and 6B.

FIG. 4 shows another cross-sectional view of the wearable device 120(taken along line A-A′ in FIG. 3A). As shown, the wearable device 120includes at least three bladders 204-A, 204-B, and 204-C, where thefirst bladder 204-A is inflated (e.g., is in a pressurized/inflatedstate) while the second and third bladders 204-B and 204-C are notinflated (e.g., are in an unpressurized state). Alternatively, thesecond and third bladders 204-B and 204-C may be partially inflated(e.g., fluid pressure is below a threshold, and therefore the second andthird bladders 204-B and 204-C are not in the pressurized/inflatedstate). The magnified views 400 and 410 illustrate the structure of thefirst bladder 204-A and the third bladder 204-C, which has the samestructure. However, the magnified views 400 and 410 illustrate how thestructure of the first bladder 204-A changes according to fluid pressurewithin the bladder 204-A (e.g., a fluid is fed into the first bladder204-A and not the third bladder 204-C). It is noted that the structureof the third bladder 204-C may be flatter in practice, and the slightlyraised structure shown in magnified view 410 is used primarily forillustrative purposes.

The magnified view 400 shows the structure of the first bladder 204-A.As shown, the first bladder 204-A includes (i) a first bellows 402-A and(ii) a second bellows 402-B positioned on top of the first bellows402-A. A surface 409 of the second bellows 402-B is the surface of thebladder 204-A that contacts the user wearing the wearable structure 202.The first bellows 402-A is coupled to the wearable structure 202 via achemical fastener 408 (e.g., an adhesive) while the second bellows 402-Bis coupled to the first bellows 402-A via another chemical fastener 408.Moreover, the first and second bellows define respective openings thatcollectively form a passage 406 that fluidically connects the firstbellows 402-A with the second bellows 402-B. In addition, the firstbellows 402-A defines another opening 404 sized to accommodate an end(e.g., a valve) of the conduit 208-A. In such an arrangement, fluid fromthe conduit 208-A enters the first bellows 402-A at the opening 404, andsubsequently, the fluid enters the second bellows 402-B, from the firstbellows 402-A, via the passage 406. The stacked arrangement of the firstand second bellows 402 facilitates a substantial expansion of thebladder 204-A in a preferred direction (e.g., in the vertical directionof FIG. 4), which cannot be achieved with a single bellows. With thisenhanced expansion of the bladder 204-A, the structure imparts asignificant force onto the user wearing the wearable device 120, whilealso minimizing the noticeability of the wearable device 120 (e.g., thewearable device 120 is lightweight and compact).

In some embodiments, a radius of the passage 406 is approximately 1 mm,and a radius of the opening 404 is also approximately 1 mm. In suchembodiments, a radius (r¹) of the bellow 402-A is approximately 8 mm(the other bellows may have the same radius, or a different radius).Various other radii are possible, and in some embodiments, the radii ofthe passage 406 and the opening 404 have a proportional relationshipwith the radii of the bellows.

While not shown, the first bladder 204-A may include a third bellowspositioned on top of the second bellows 402-B. In such embodiments, thesecond bellows 402-B is modified to have the same structure as the firstbellows 402-A, and a structure of the third bellows matches thestructure of the second bellows 402-B shown in FIG. 4. A third bellows(or even a fourth bellows) can be used when the wearable device 120 isworn on a portion of the user's body where the wearable device 120 tendsto separate away from the user's skin. In other words, it is difficultto maintain direct contact between the bladders and the user skin. Thethird bellows is therefore needed to create greater expansion in thepreferred direction, so that a force can be imparted onto the user.

In some embodiments, the first bellows 402-A is identical to the secondbellows 402-B (aside from the second bellows 402-B not having multipleopenings). For example, in the illustrated embodiment, the diameter(i.e., width) of each bellows is approximately the same. Additionally,when inflated/pressurized, each bellows expands vertically byapproximately the same amount. In other embodiments, however, the firstbellows 402-A differs from the second bellows 402-B in some way. Forexample, a diameter (i.e., width) of each bellows may differ. Toillustrate, the second bellows 402-B may be narrower than the firstbellows 402-A (or vice versa), such that the first bellows 402-A and thesecond bellows 402-B form a triangular shape (e.g., substantiallyfrustoconical). In another example, the first bellows 402-A may be madefrom a first material while the second bellows 402-B may be made from asecond material that differs from the first material. The use ofdifferent materials can influence the shape of the bladder 204 in theinflated state. For example, material properties (e.g., elastic versusinelastic or less elastic) of the first and second bellows cancontribute to the shape taken by the bladder 204. Additionally, materialthickness can contribute to the shape taken by the bladder 204.

As noted above, the third bladder 204-C has the same structure as thefirst bladder 204-A. For example, first and second bellows of the thirdbladder 204-C define respective openings that collectively form apassage 416 that fluidically connects the first bellows 412-A with thesecond bellows 412-B. In addition, the first bellows 412-A definesanother opening 414 sized to accommodate an end of the conduit 208-C.For the sake of brevity, the remaining description of the third bladder204-C's components is not repeated here.

FIGS. 5A-5C show cross-sectional views of a representative bladder 204in accordance with some embodiments. The representative bladder 204includes a structure similar to the structure of the bladders discussedin FIG. 4. For example, the bladder includes (i) a first bellows 402-Aand (ii) a second bellows 402-B positioned on top of the first bellows402-A. The bladder 204 also includes one or more sensors 430 integratedwith the first bellows 402-A and the second bellows 402-B. The sensors430 are configured to monitor a state of the bladder 204. For example,the sensors 430 are configured to provide sensor data to a controller214 based on the monitored state of the bladder 204. Specifically, thesensor 430 may provide data to the controller that the bladder 204 hasbeen inflated by a first amount, and in response to receiving the data,the controller may further increase (or decrease) inflation of thebladder 204. In this way, the sensors 430 create a feedback loop thatimproves performance of the wearable device 120. The sensor data mayinclude one or more of: (i) measurements of the bladder's expansion,(ii) measurements of the bladder's contraction, and (iii) measurementsof the fluid pressure within the bladder.

Some embodiments use displacement sensors 430. For example, the sensor430 includes an upper component and a lower component, and the sensor430 is configured to monitor a distance between the upper component(e.g., metal plate) and the lower component (e.g., another metal plate).In such embodiments, the displacement sensor may measure capacitance.Alternatively, or in addition, in some embodiments, the sensor 430 is aforce/pressure sensor. In addition, in some embodiments, each bladder204 of the wearable device 120 includes an instance of the sensor 430.In such embodiments, each sensor 430 may provide data to the controllerthat its respective bladder 204 has been inflated by a first amount, andin response to receiving the data, the controller may further increase(or decrease) inflation of one or more of the bladders 204. It is alsonoted that the controller may forgo increasing (or decreasing) inflatingwhen the data indicates that the bladder is at the desired position orpressure.

In some embodiments, the sensor 430 can be used to turn the bladder 204into an input device (i.e., a button). For example, with reference toFIG. 5A, the bladder 204 is unpressurized (i.e., is in an unpressurizedstate). In such a state, the components of the sensor 430 are separatedby a first distance (D¹), and the sensor 430 provides first sensor datato the controller indicating the first distance (D¹) of separation.However, with reference to FIG. 5B, the bladder 204 is pressurized(“Fluid In”) (i.e., is in a pressurized state). As discussed above, thebladder 204 is configured to expand and contract according to fluidpressure within the bladder 204. Thus, in the pressurized state, thecomponents of the sensor 430 are separated by a second distance (D²),which is greater than the first distance (D¹), and the sensor 430provides second sensor data to the controller indicating the seconddistance (D²) of separation. In embodiments where the sensor 430 is adisplacement sensor, the first and second sensor data may be capacitancemeasurements, which correspond to a distance (i.e., a gap) between theupper and lower components of the displacement sensor 430.

With reference to FIG. 5C, the user presses (“Input Force”) on thebladder 204 while the bladder 204 is inflated (e.g., while the bladder204 is in the pressurized state). In doing so, the user forces some ofthe fluid out of the bladder 204, thereby causing the components of thesensor 430 to be separated by a third distance (D³), which is less thanthe second distance (D²). In response, the sensor 430 provides thirdsensor data to the controller indicating the third distance (D³) ofseparation. In some embodiments, a different between the second distance(D²) and third distance (D³) satisfies a touch threshold. Thecontroller, upon receiving the third sensor data and with theunderstanding that the bladder is in the pressurized state, processesthe third data sensor as a touch input (e.g., in response to determiningthat the difference between the second distance (D²) and third distance(D³) satisfies the touch threshold). In this way, a user can press aninflated bladder, as if it were a button, and the sensor 430 can providedata to the controller indicating depression of the bladder, which thecontroller subsequently processes as a button press. The bladder 204 isinflated during the touch input, which provides tactile feedback to theuser that resembles depression of a physical button.

In those embodiments where the sensor 430 is a force/pressure sensor,the first and second sensor data indicate an amount of force applied tothe sensor 430, as opposed to a distance separating components of thesensor 430. The force sensor 430 can indicate to the controller that thebladder is inflated (or is sufficiently inflated, or is deflated). Theforce sensor 430 can also measure input forces applied to the bladder204 by the user. Therefore, the force applied to the sensor 430 in FIG.5C, caused by the user pressing on the bladder 204, is different from(e.g., greater than) than the force applied to the sensor 430 in FIG.5B. The controller, upon receiving the third sensor data from the forcesensor 430 (and in some embodiments with the understanding that thebladder is in the pressurized state), processes the third data sensor asa touch input when the third sensor data indicates that the amount offorce applied to the sensor 430 satisfies a touch threshold. In someembodiments, the force/pressure sensor is positioned on the surface 409of outermost bellows 402, instead of the sensor position illustrated inFIGS. 5A-5C.

To summarize, the force a respective bladder 204 exerts on a userdepends on fluid pressure (e.g., supply pressure) and the distance atwhich the bladder contacts the user. To ensure that the same force isprescribed to all users (e.g., to avoid large force deviations from userto user), the wearable device 120 can include one or more sensors 430(e.g., each bladder 204 includes a sensor 430) to monitor the state ofthe bladder 204, and provide feedback regarding the force prescribed tothe user (or measurements of the bladder's expansion, and theninterpolate force from those measurements). The sensor 430 may bepositioned in various locations within a respective bladder 204, and theillustrated example is one possible location.

An example method is provided to give additional context to thedescription of FIGS. 5A-5C. The method includes instructing, by thewearable device 120 or the computer system 130, a source 210 totransition at least one bladder 204 of the wearable device 120 from anunpressurized state to a pressurized state, where the bladder 204 isassociated with a function when transitioned to the pressurized state.The method also includes, while the inflatable bladder is in thepressurized state: (i) detecting, by a sensor 430 of the wearable device120, depression (e.g., the “Input Force” in FIG. 5C) of the inflatedbladder 204, and (ii) generating, by the sensor 430, sensor data basedon the detecting. The sensor data may include various measurements,including one or more of (i) measurements of the bladder's expansion,(ii) measurements of the bladder's contraction, (iii) measurements ofthe fluid pressure within the bladder, and (iv) measurements of pressureon the bladder. In some embodiments, the wearable device 120 sends thegenerated sensor data to the computer system 130, and the followingsteps are performed by the computer system 130. In some embodiments, thefollowing steps may be performed by the wearable device 120.

The method also includes, in response to detecting the depression of theinflatable bladder: (i) determining whether the magnitude of thedepression satisfies a touch threshold, based on the sensor data, and(ii) in accordance with a determination that the magnitude of thedepression satisfies the touch threshold, executing the function.Importantly, depression of the bladder 204, while the bladder 204 is inthe pressurized state (i.e., while the bladder 204 is inflated),provides tactile feedback to the user (e.g., depression of the bladderresembles depression of a physical button). In some embodiments, thefunction may be a function at the wearable device 120 (e.g., silencingan alert generated by the wearable device 120), while in otherembodiments executing the function includes sending an instruction toanother electronic device (e.g., the computer system 130 or thehead-mounted display 110) according to the function. For example, analert (or some other message) may be displayed on the head-mounteddisplay 110, and the user may use the wearable device 120 to acknowledgethe alert (e.g., select an affordance displayed in the message).

In some embodiments, the wearable device 120 includes a display. Forexample, the artificial-reality device 900 in FIG. 9 includes a display904. In such embodiments, executing the function includes modifying auser interface displayed on the display.

In some embodiments, the sensor 430 is used to measure (i.e., evaluate)coupling (i.e., fit) of the wearable device 120 with the user's body.For example, if sensor data generated by the sensor 430 indicates thatcontact (measured in force/pressure measurements) between of thewearable device 120 and the user's body in below a pressure threshold,the controller can in turn inflate (partially or fully) one or morebladders 204 to create additional contact (i.e., friction) between thewearable device 120 and the user's body (i.e., so that contact betweenthe wearable device 120 and the user's body satisfies the pressurethreshold). Moreover, in some embodiments, IMU sensors 124 of thewearable device 120 can provide additional sensor data to the controllerindicating undesired movement of the wearable device 120 (e.g., the IMUsensor data may indicate that the wearable device 120 slid down theuser's arm slightly when the user raised his hand). Accordingly, thecontroller can inflate (partially or fully) one or more bladders 204 tocreate additional contact (i.e., friction) between the wearable device120 and the user's body to prevent the detected slippage.

FIGS. 6A and 6B show examples of a representative wearable device 120 indifferent states in accordance with some embodiments. As shown in FIGS.6A and 6B, the wearable device 120 includes a plurality of bladders204-A, 204-B, . . . , 204-H integrated with a wearable structure 202. Insome embodiments, a center-to-center distance between adjacent bladders204 is approximately 24 mm. Each bladder 204 is fluidically coupled witha distinct conduit 208. FIG. 6A shows each bladder 204 of the wearabledevice 120 unpressurized (i.e., each bladder 204 is in an unpressurizedstate). In contrast, FIG. 6B shows a few of the bladders 204 pressurized(i.e., in a pressurized state). For example, bladders 204-A, 204-E, and204-H are inflated to a threshold pressure, such that these bladders 204are deemed to be in a pressurized state. Thus, a user wearing thewearable device 120 of FIG. 6B, as shown in FIG. 6C, experiencesmultiple haptic stimulations resulting from the bladders 204-A, 204-E,and 204-H contacting his or her body (e.g., the bladder 204-E in FIG. 6Cis touching the user's wrist as a result of being inflated to thethreshold pressure). It is noted that the conduits 208 shown in FIGS.6A-6C may be integrated with the wearable structure 202 (or some othergarment) to hide the conduits 208 from view.

FIG. 6D shows a graph 650 illustrating Force (N) applied to a user basedon a Pressure (psi) and a Distance (mm). “Pressure” corresponds to asupply pressure input into a respective bladder 204, while “Distance”corresponds to a separation distance between the respective bladder 204and the user. As shown, the greatest force (e.g., greater than 10 N) isapplied to the user when “Distance” is minimized and “Pressure” ismaximized. The graph 650 also shows that, at the same pressure (e.g., 15psi), different forces are applied to the user (e.g., as separationdistance increases, force applied decreases). Thus, another importantfactor in how much force can be applied to a user is a bladder'sexpandability/extendibility. For example, if a bladder 204 can onlyextend 4 mm and the separation distance is also 4 mm, then the amount offorce capable of being applied to the user will be essentially zero.

FIGS. 7A-7H illustrate a process of fabricating an example wearabledevice 120 in accordance with some embodiments. The process begins atstep 700 by providing a polymer layer 702. In some embodiments, thepolymer layer 702 is made from an elastic polymer, including variousthermoplastic elastomers, such as thermoplastic polyurethane (TPU) andthe like (e.g., polyester TPU). TPU (and similar materials) is thepreferred material because TPU is flexible, yet durable and punctureresistant. As shown, the polymer layer 702 includes multiple conduitinsertion holes/openings 704-A, 704-B, . . . 704-P and multiple bladderaccess openings 706-A, 706-B, . . . 706-P. Each of the bladder accessopenings 706-A, 706-B, . . . 706-P is located opposite an opening 404(and opening 414) in FIG. 4. As shown in FIG. 7A, the conduit insertionholes 704-A, 704-B, . . . 704-P are located at a distance D from an edgeof the polymer layer 702. In some embodiments, the distance D isapproximately half the width of the polymer layer 702. For example, ifthe polymer layer 702 is 40 mm wide, then the conduit insertion holes704-A, 704-B, . . . 704-P are located at 20 mm from the edge of thepolymer layer 702. In some other embodiments, the distance D is greaterthan (or less than) half the width of the polymer layer 702. Forexample, if the polymer layer 702 is 40 mm wide, then the conduitinsertion holes 704-A, 704-B, . . . 704-P may be located at 30 mm (orsome other location) from the edge of the polymer layer 702. Variousother widths are possible, and 40 mm is merely one possible example thatis used herein primarily to provide context.

In the illustrated embodiments, the diameter of each of the bladderaccess openings 706-A, 706-B, . . . 706-P is greater than the diameterof each of the conduit insertion holes 704-A, 704-B, . . . 704-P.However, in other embodiments, the diameter of each of the bladderaccess openings 706-A, 706-B, . . . 706-P may be less than or equal tothe diameter of each of the conduit insertion holes 704-A, 704-B, . . .704-P. The diameter of each of the conduit insertion holes 704-A, 704-B,. . . 704-P is dependent on (and corresponds to) the diameter of theconduit 208 inserted therein.

At this stage, the polymer layer 702 defines the bladder access openings706-A, 706-B, . . . 706-P (e.g., circular, or some other shape) and theconduit insertion holes 704-A, 704-B, . . . 704-P (e.g., circular, orsome other shape). The polymer layer 702 includes opposing first andsecond surfaces. Next, multiple adhesives 708-A, 708-B, . . . 708-P areattached to (e.g., deposited on) the first surface of the polymer layer702. Specifically, a respective adhesive 708 is aligned with one of themultiple bladder access openings 706-A, 706-B, . . . 706-P (e.g., afirst adhesive 708-A and a first opening 706-A are coaxially aligned).In some embodiments, the adhesive 708 is printed onto the polymer layer702, whereas in other embodiments the adhesive 708 is placed onto thepolymer layer 702. In addition, in some embodiments, the processincludes heating the adhesive 708 during or after attaching the adhesive708 to the first surface of the polymer layer 702. The adhesive 708 maybe various adhesives (e.g., epoxy or glue) suitable for couplingpolymers (e.g., thermoplastics) together. Each adhesive 708 has a shapethat compliments the shape of the bladder access openings 706. Forexample, in the illustrated embodiments, the bladder access openings706-A, 706-B, . . . 706-P are circular, and therefore, each adhesive 708is ring shaped (e.g., annular). Thus, each adhesive 708 has an inner andouter diameter.

The process further includes, at step 710, attaching multiple firstbladder layers 712-A, 712-B, . . . 712-P to the first surface of thepolymer layer 702. Specifically, a respective first bladder layer 712 ispositioned on one of the deposited adhesives 708 and also aligned withone of the multiple bladder access openings 706-A, 706-B, . . . 706-P(e.g., the first bladder layer 712-A, the first adhesive 708-A, and thefirst opening 706-A are coaxially aligned). The first bladder layer 712corresponds to the layer of the first bellows 402-A that defines theopening 404 in FIG. 4. Thus, each of the multiple first bladder layers712-A, 712-B, . . . 712-P has a central opening, which is an instance ofthe opening 404 in FIG. 4. The diameter of the central opening may bethe same as or different from (e.g., less than) the diameter of thebladder access opening 706.

As shown in FIG. 7B, the outer diameter of each first bladder layer 712is greater than the outer diameter of the corresponding adhesive 708(but the inner diameter of the corresponding adhesive 708 issubstantially the same as the diameter of the bladder access opening706). In this way, only an inner region of the first bladder layer 712is fixed to the polymer layer 702, and consequently (as shown in FIG.4), the outer region of the first bladder layer 712 lifts away from thepolymer layer 702 when the first bellows 402-A is pressurized. It isnoted that, in other embodiments, the outer diameter of each firstbladder layer 712 is substantially the same as the outer diameter of thecorresponding adhesive 708. In such embodiments, the first bladder layer712 is prevented from lifting away from the polymer layer 702 when thefirst bellows 402 is pressurized.

In some embodiments, attaching the multiple first bladder layers 712-A,712-B, . . . 712-P with the first surface of the polymer layer 702includes pressing the multiple first bladder layers 712-A, 712-B, . . .712-P and the first surface of the polymer layer 702 together using aheat press (e.g., user operated or automated). The pressing may last forapproximately 30 seconds and may be performed at approximately 20pounds-per-square inch (psi). Various other times and pressures may beused as well. The pressing ensures that the adhesive 708 adheres to thefirst bladder layer 712, thereby reducing the likelihood of delaminationand air leaks during use. Additionally, the adhesive 708 may requireheat to fully cure (e.g., 260° F. applied to cure the adhesive 708).

The process further includes, at step 720, attaching multiple adhesives722-A, 722-B, . . . 722-P to the first bladder layers 712. Specifically,a respective adhesive 722 is aligned with one of the multiple firstbladder layers 712-A, 712-B, . . . 712-P. In some embodiments, theadhesive 722 is printed onto the first bladder layer 712, whereas inother embodiments the adhesive 722 is placed onto the first bladderlayer 712. In addition, in some embodiments, the process includesheating the adhesive 722 during or after attaching the adhesive 722 tothe first bladder layer 712. As shown in FIG. 7C, the multiple adhesives722-A, 722-B, . . . 722-P are ring shaped (e.g., annular). Thus, eachadhesive 722 has an inner diameter and an outer diameter. The outerdiameter of the multiple adhesives 722-A, 722-B, . . . 722-P matches theouter diameter of the first bladder layer 712. In addition, the multipleadhesives 722-A, 722-B, . . . 722-P are thin rings (e.g., the differencebetween the inner and outer diameters of the adhesive 722 is smallrelative to a difference between the inner and outer diameters of theadhesive 708). In some embodiments, the multiple adhesives 722-A, 722-B,. . . 722-P are 2 mm wide. Some advantages of the thin ring shape arediscussed below with reference to step 730.

The process further includes, at step 730, attaching multiple secondbladder layers 732-A, 732-B, . . . 732-P with the partially fabricateddevice. Specifically, a respective second bladder layer 732 ispositioned on each one of the deposited adhesives 722 and each one ofthe first bladder layers 712, and also aligned with one of the multiplebladder access openings 706-A, 706-B, . . . 706-P. The second bladderlayer 732 corresponds to the layer of the first bellows 402-A thatdefines part of the passage 406 in FIG. 4. In the illustratedembodiments (e.g., in steps 720 and 730), the adhesive 722 is locatedalong a perimeter of the first bladder layer 712, and consequently (asshown in FIG. 4 with reference to the first bellows 402-A), only aperimeter (i.e., edge region) of the first bladder layer 712 is coupledwith (e.g., adhered to) a perimeter (i.e., edge region) of the secondbladder layer 732. The thin ring shape of the adhesive 722 is used tomaximize vertical expansion of the first bellows 402-A in FIG. 4 (andthe other bellows shown in FIG. 4). It is noted that if less verticalexpansion of a bellows is desired, then a width of the adhesive 722(i.e., the difference between the inner and outer diameters) can beincreased.

In some embodiments, attaching the multiple second bladder layers 732-A,732-B, . . . 732-P includes pressing the multiple first bladder layers732-A, 732-B, . . . 732-P and the partially fabricated device togetherusing a heat press (e.g., user operated or automated). The pressing maylast for approximately 30 seconds and may be performed at approximately20 pounds-per-square inch (psi). Various other times and pressures maybe used as well. The pressing ensures that the adhesive 722 adheres tothe second bladder layer 732, thereby reducing the likelihood ofdelamination and air leaks during use. Additionally, the adhesive 722may require heat to fully cure.

In some embodiments, if only a single tier of bellows is desired, step730 is replaced with step 740, and the process is completed. If multipletiers of bellows are desired, the process continues, as described below.

The discussion above for steps 700-730 can be repeated any number oftimes to created additional bellows. For example, with reference to FIG.4, the discussion above for steps 700-730 details the fabrication of afirst tier of bellows, such as the bellows 402-A and the bellows 412-Ain FIG. 4. The steps can, if desired, then repeat to create a secondtier of bellows, such as the bellows 402-B and the bellows 412-B in FIG.4. Importantly, if the second tier of bellows is the final tier ofbellows to be fabricated, then step 740 replaces step 730. However, if athird tier of bellows is desired, then the second tier of bellows iscreated using steps 700 through 730. The discussion below describes howfabrication of the wearable device 120 is completed.

At this stage in the process (at step 740 in FIG. 7E), and for ease ofdiscussion, a first tier of bellows has been fabricated (as describedabove in steps 700-730), and a second tier of bellows is partiallyfabricated (steps 700-720 have been repeated). Thus, the partiallycompleted second tier of bellows includes: (i) multiple adhesives (e.g.,instances of the adhesives 708) attached to each of the second bladderlayers 732 from step 730, (ii) multiple third bladder layers (e.g.,instances of the first bladder layers 712) positioned on the multipleadhesives and the second bladder layers 732 from step 730 (i.e., thethird bladder layers and the second bladder layers are adjacent layers),and (iii) multiple thin-ring adhesives (e.g., instances of the adhesives722) attached to perimeters of the third bladder layers.

Next, multiple top bladder layers 742-A, 742-B, . . . 742-P arepositioned on the multiple thin-ring adhesives and the third bladderlayers (i.e., the third bladder layers and the top bladder layers areadjacent layers). To provide some context, the top bladder layer 742corresponds to the top layer (e.g., surface 409) of the second bellows402-B in FIG. 4. The top bladder layer 742 does not include anyopenings, in contrast to the other bladder layers discussed above, eachof which has an opening. Thus, with reference to FIG. 4, the top bladderlayer 742 seals the first bellows 402-A and the second bellows 402-B.

The process further includes, at step 750, connecting multiple conduits208-A, 208-B, . . . 208-P to the multi-tier structure fabricated throughstep 740. As shown, an adhesive layer 752 is also provided, which isconfigured to adhere to the polymer layer 702. The adhesive layer 752 isused to secure the multiple conduits 208-A, 208-B, . . . 208-P to thepolymer layer 702, and also create an air tight seal with the polymerlayer 702. The adhesive layer 752 has multiple bladder access openings754-A, 754-B, . . . 754-P and multiple puncture points 756-A, 756-B, . .. 756-P. To connect the conduits 208, each of the multiple conduits208-A, 208-B, . . . 208-P is fed through one of the conduit insertionholes 704-A, 704-B, . . . 704-P and then through one of the puncturepoints 756-A, 756-B, . . . 756-P (as illustrated by the arrow directionin FIG. 7F). Thereafter, an end of each conduit 208 is inserted in andcoupled to one of the bladder access openings 754-A, 754-B, . . . 754-P(e.g., arrows of conduit lines 208 shown in FIG. 7F loop back upwards tothe corresponding opening 754 after behind fed through the correspondingpuncture point 756). The puncture points 756-A, 756-B, . . . 756-P areshaped openings that are configured to prevent the conduit 208 fromsliding in a direction opposite the feed direction shown in FIG. 7F. Insome embodiments, the end of each conduit 208 includes a valve, which isdescribed above with reference to FIGS. 3A and 3B.

The process further includes (at step 760) folding the polymer layer 702and the adhesive layer 752 in the manner shown in FIG. 7G. The foldedstructure is then pressed together, which may or may not include heat.In some embodiments, the fold is made along a center line 751 of thepolymer layer 702, shown in FIG. 7F. Alternatively, in some embodiments,the fold is made closer to or farther from the bladder access openings706-A, 706-B, . . . 706-P. The multiple conduit insertion holes 704-A,704-B, . . . 704-P may be positioned along the fold line or offset fromthe fold line in either direction.

Because the adhesive layer 752 forms the bottom of the structure, theadhesive layer 752 folds onto and adheres to itself. In someembodiments, after or during the folding step 760, heat and/or pressureis applied to the folded structure. The heat and/or pressure ensure thatthe adhesive layer 752 adheres to itself, thereby reducing thelikelihood of delamination and air leaks during use.

FIG. 7H shows a top view of a finished wearable device 120. It is notedthat the polymer layer 702 and the adhesive layer 752 together compose,at least partially, the wearable structure 202. The wearable structure202 may include one or more additional layers, such as material that atleast partially conceals the polymer layer 702 (and potentially thebellows). For example, the wearable structure 202 can also includefabric or other wearable material, such as leather or plastic (e.g., thewearable device 120 may be a fitness or smart watch). Moreover, the oneor more additional layers may include one or more instances of thepolymer layer 702 and/or the adhesive layer 752.

It is noted that the process described above is merely one exampleprocess for fabricating the wearable devices 120 discussed herein. Inother embodiments, the bladders 204 of the wearable device 120 (orlayers that form the bladders 204) are folded in a predetermined manner(e.g., origami-type bellows). The folds allow the bellows to lie flatwhen unpressurized and expand, according to the design of the folds,when pressurized. Put another way, the bellows collapses on itself(i.e., folds) when unpressurized, and the bellows unfolds itself whenpressurized. In some embodiments, the folds are similar to the structureof an accordion's bellows.

FIG. 8 is a flow diagram illustrating a method 800 of creating hapticstimulations in accordance with some embodiments. The steps of themethod 800 may be performed (802) by a computer 130. FIG. 8 correspondsto instructions stored in a computer memory or computer readable storagemedium (e.g., the memory of the computer system 130). For example, theoperations of the method 800 are performed, at least in part, by acommunication interface (e.g., similar to the communication interface126) and a virtual-reality/augment reality generation module (e.g., partof the engine 134). It is noted that the method described below can beimplemented with any of the wearable devices discussed above.

The method 800 includes generating (804) an instruction that correspondsto media (e.g., visual data) to be displayed by a head-mounted display110 in communication the computer system (and/or corresponds toinformation received from one or more sensors 124 of the wearable device120 and/or information received from one or more sensors 114 of thehead-mounted display 110). In some embodiments, the computer systemgenerates the instruction based on information received from the sensorson the wearable device. Alternatively or in addition, in someembodiments, the computer system generates the instruction based oninformation received from the sensors on the head-mounted display. Forexample, cameras (or other sensors 114) on the head-mounted display maycapture movements of the wearable device, and the computer system canuse this information when generating the instruction.

The method 800 further includes sending (806) the instruction to a fluidsource 210 in communication with the computer system (e.g., send theinstruction in a communication signal from a communication interface).The instruction, when received by the source, causes the source tochange a pressure inside one or more bladders of the wearable device120. In doing so, a wearer of the wearable device experiences a hapticstimulation that corresponds to the visual data. In some embodiments,the instruction specifies the change in the pressure to be made by thesource. In some situations, instead of the computer system sending theinstruction to the source, the computer system sends the instruction tothe wearable device. In response to receiving the instruction, thewearable device sends the instruction to the source. The source isdiscussed in further detail above with reference to FIG. 2A.

After (or while, or before) sending the instruction, the method 800 alsoincludes sending (808) the media to the head-mounted display. Forexample, the head-mounted display may receive visual data from thecomputer system, and may in turn display the visual data on itsdisplay(s). As an example, if the computer system receives informationfrom the sensors 124 of the wearable device 120 that the user has closedhis fingers around a position corresponding to a coffee mug in thevirtual environment and raised his hand, a simulated hand in avirtual-reality application picks up the virtual coffee mug and lifts itto a corresponding height. Generating and sending media is discussed infurther detail above with reference to FIG. 1.

In conjunction with displaying the visual data (or other media), one ormore bladders of the wearable device are inflated or deflated to thedesired pressure (as noted above). As an example, the wearable devicemay include: (i) a wearable structure attachable to a portion of auser's body; (ii) a plurality of bladders, integrated with the wearablestructure, configured to expand and contract according to fluid pressurewithin each bladder, where each bladder of the plurality of bladdersdelivers (e.g., imparts) a haptic stimulation to the user wearing thewearable structure when the bladder expands a threshold amount; and(iii) at least one conduit configured to transport a fluid from thesource to one or more bladders of the plurality of bladders, where thefluid from the source increases the fluid pressure within at least theone or more bladders. Accordingly, in this particular example, when thesource changes the pressure inside one or more bladders of the wearabledevice (e.g., increases the pressure and expands the bladder by thethreshold amount), each of the one or more bladders imparts a hapticstimulation to the user wearing the wearable structure.

In some embodiments, the computer and the head-mounted display togetherform an artificial-reality system. Furthermore, in some embodiments, theartificial-reality system is a virtual-reality system 1100.Alternatively, in some embodiments, the artificial-reality system is anaugmented-reality system 1000 or artificial-reality system 900. In someembodiments, the visual data presented to the user by theartificial-reality system includes visual media displayed on one or moredisplays of the virtual-reality or augmented-reality system.

Embodiments of this disclosure may include or be implemented inconjunction with various types of artificial-reality systems. Artificialreality may constitute a form of reality that has been altered byvirtual objects for presentation to a user. Such artificial reality mayinclude and/or represent virtual reality (VR), augmented reality (AR),mixed reality (MR), hybrid reality, or some combination and/or variationof one or more of the these. Artificial-reality content may includecompletely generated content or generated content combined with captured(e.g., real-world) content. The artificial reality content may includevideo, audio, haptic feedback, or some combination thereof, any of whichmay be presented in a single channel or in multiple channels (such asstereo video that produces a three-dimensional effect to a viewer).Additionally, in some embodiments, artificial reality may also beassociated with applications, products, accessories, services, or somecombination thereof, which are used, for example, to create content inan artificial reality and/or are otherwise used in (e.g., to performactivities in) an artificial reality.

Artificial-reality systems may be implemented in a variety of differentform factors and configurations. Some artificial reality systems aredesigned to work without near-eye displays (NEDs), an example of whichis the AR system 900 in FIG. 9. Other artificial reality systems includean NED, which provides visibility into the real world (e.g., the ARsystem 1000 in FIG. 10) or that visually immerses a user in anartificial reality (e.g., the VR system 1100 in FIG. 11). While someartificial reality devices are self-contained systems, other artificialreality devices communicate and/or coordinate with external devices toprovide an artificial reality experience to a user. Examples of suchexternal devices include handheld controllers, mobile devices, desktopcomputers, devices worn by a user (e.g., a wearable device 120), devicesworn by one or more other users, and/or any other suitable externalsystem.

FIGS. 9-11 provide additional examples of the devices used in the system100. The AR system 900 in FIG. 9 generally represents a wearable devicedimensioned to fit about a body part (e.g., a head) of a user. The ARsystem 900 may include the functionality of the wearable device 120, andmay include additional functions not described above. As shown, the ARsystem 900 includes a frame 902 (e.g., a band or wearable structure 202)and a camera assembly 904, which is coupled to the frame 902 andconfigured to gather information about a local environment by observingthe local environment (and may include a display 904 that displays auser interface). The AR system 900 may also include one or moretransducers. In one example, the AR system 900 includes outputtransducers 908(A) and 908(B) and input transducers 910. The outputtransducers 908(A) and 908(B) may provide audio feedback, hapticfeedback, and/or content to a user, and the input audio transducers maycapture audio (or other signals/waves) in a user's environment.

In some embodiments, the AR system 900 includes one or more instances ofthe wearable device 120 disclosed herein. For example, the AR system 900may include one or more bladders 204 on the inside of the frame 902 (asshown) and also one or more bladders 204 on the outside of the frame 902(not shown). In this way, the AR system 900 is able to create hapticstimulations, as discussed in detail above, and also include the novelinput device described above with reference to FIGS. 5A-5C.

Thus, the AR system 900 does not include a near-eye display (NED)positioned in front of a user's eyes. AR systems without NEDs may take avariety of forms, such as head bands, hats, hair bands, belts, watches,wrist bands, ankle bands, rings, neckbands, necklaces, chest bands,eyewear frames, and/or any other suitable type or form of apparatus.While the AR system 900 may not include an NED, the AR system 900 mayinclude other types of screens or visual feedback devices (e.g., adisplay screen integrated into a side of the frame 902).

The embodiments discussed in this disclosure may also be implemented inAR systems that include one or more NEDs. For example, as shown in FIG.10, the AR system 1000 may include an eyewear device 1002 with a frame1010 configured to hold a left display device 1015(A) and a rightdisplay device 1015(B) in front of a user's eyes. The display devices1015(A) and 1015(B) may act together or independently to present animage or series of images to a user. While the AR system 1000 includestwo displays, embodiments of this disclosure may be implemented in ARsystems with a single NED or more than two NEDs.

In some embodiments, the AR system 1000 may include one or more sensors,such as the sensors 1040 and 1050 (e.g., instances of the sensors 114 inFIG. 1). The sensors 1040 and 1050 may generate measurement signals inresponse to motion of the AR system 1000 and may be located onsubstantially any portion of the frame 1010. Each sensor may be aposition sensor, an inertial measurement unit (IMU), a depth cameraassembly, or any combination thereof. The AR system 1000 may or may notinclude sensors or may include more than one sensor. In embodiments inwhich the sensors include an IMU, the IMU may generate calibration databased on measurement signals from the sensors. Examples of the sensorsinclude, without limitation, accelerometers, gyroscopes, magnetometers,other suitable types of sensors that detect motion, sensors used forerror correction of the IMU, or some combination thereof. Sensors arealso discussed above with reference to FIG. 1.

The AR system 1000 may also include a microphone array with a pluralityof acoustic sensors 1020(A)-1020(J), referred to collectively as theacoustic sensors 1020. The acoustic sensors 1020 may be transducers thatdetect air pressure variations induced by sound waves. Each acousticsensor 1020 may be configured to detect sound and convert the detectedsound into an electronic format (e.g., an analog or digital format). Themicrophone array in FIG. 10 may include, for example, ten acousticsensors: 1020(A) and 1020(B), which may be designed to be placed insidea corresponding ear of the user, acoustic sensors 1020(C), 1020(D),1020(E), 1020(F), 1020(G), and 1020(H), which may be positioned atvarious locations on the frame 1010, and/or acoustic sensors 1020(I) and1020(J), which may be positioned on a corresponding neckband 1005. Insome embodiments, the neckband 1005 is an example of the computer system130.

The configuration of the acoustic sensors 1020 of the microphone arraymay vary. While the AR system 1000 is shown in FIG. 10 having tenacoustic sensors 1020, the number of acoustic sensors 1020 may begreater or less than ten. In some embodiments, using more acousticsensors 1020 may increase the amount of audio information collectedand/or the sensitivity and accuracy of the audio information. Incontrast, using a lower number of acoustic sensors 1020 may decrease thecomputing power required by a controller 1025 to process the collectedaudio information. In addition, the position of each acoustic sensor1020 of the microphone array may vary. For example, the position of anacoustic sensor 1020 may include a defined position on the user, adefined coordinate on the frame 1010, an orientation associated witheach acoustic sensor, or some combination thereof.

The acoustic sensors 1020(A) and 1020(B) may be positioned on differentparts of the user's ear, such as behind the pinna or within the auricleor fossa. Or, there may be additional acoustic sensors on or surroundingthe ear in addition to acoustic sensors 1020 inside the ear canal.Having an acoustic sensor positioned next to an ear canal of a user mayenable the microphone array to collect information on how sounds arriveat the ear canal. By positioning at least two of the acoustic sensors1020 on either side of a user's head (e.g., as binaural microphones),the AR device 1000 may simulate binaural hearing and capture a 3D stereosound field around about a user's head. In some embodiments, theacoustic sensors 1020(A) and 1020(B) may be connected to the AR system1000 via a wired connection, and in other embodiments, the acousticsensors 1020(A) and 1020(B) may be connected to the AR system 1000 via awireless connection (e.g., a Bluetooth connection). In still otherembodiments, the acoustic sensors 1020(A) and 1020(B) may not be used atall in conjunction with the AR system 1000.

The acoustic sensors 1020 on the frame 1010 may be positioned along thelength of the temples, across the bridge, above or below the displaydevices 1015(A) and 1015(B), or some combination thereof. The acousticsensors 1020 may be oriented such that the microphone array is able todetect sounds in a wide range of directions surrounding the user wearingAR system 1000. In some embodiments, an optimization process may beperformed during manufacturing of the AR system 1000 to determinerelative positioning of each acoustic sensor 1020 in the microphonearray.

The AR system 1000 may further include or be connected to an externaldevice (e.g., a paired device), such as a neckband 1005. As shown, theneckband 1005 may be coupled to the eyewear device 1002 via one or moreconnectors 1030. The connectors 1030 may be wired or wireless connectorsand may include electrical and/or non-electrical (e.g., structural)components. In some cases, the eyewear device 1002 and the neckband 1005may operate independently without any wired or wireless connectionbetween them. While FIG. 10 illustrates the components of the eyeweardevice 1002 and the neckband 1005 in example locations on the eyeweardevice 1002 and the neckband 1005, the components may be locatedelsewhere and/or distributed differently on the eyewear device 1002and/or the neckband 1005. In some embodiments, the components of theeyewear device 1002 and the neckband 1005 may be located on one or moreadditional peripheral devices paired with the eyewear device 1002, theneckband 1005, or some combination thereof. Furthermore, the neckband1005 generally represents any type or form of paired device. Thus, thefollowing discussion of neckband 1005 may also apply to various otherpaired devices, such as smart watches, smart phones, wrist bands, otherwearable devices, hand-held controllers, tablet computers, or laptopcomputers.

Pairing external devices, such as a neckband 1005, with AR eyeweardevices may enable the eyewear devices to achieve the form factor of apair of glasses while still providing sufficient battery and computationpower for expanded capabilities. Some or all of the battery power,computational resources, and/or additional features of the AR system1000 may be provided by a paired device or shared between a paireddevice and an eyewear device, thus reducing the weight, heat profile,and form factor of the eyewear device overall while still retainingdesired functionality. For example, the neckband 1005 may allowcomponents that would otherwise be included on an eyewear device to beincluded in the neckband 1005 because users may tolerate a heavierweight load on their shoulders than they would tolerate on their heads.The neckband 1005 may also have a larger surface area over which todiffuse and disperse heat to the ambient environment. Thus, the neckband1005 may allow for greater battery and computation capacity than mightotherwise have been possible on a standalone eyewear device. Becauseweight carried in the neckband 1005 may be less invasive to a user thanweight carried in the eyewear device 1002, a user may tolerate wearing alighter eyewear device and carrying or wearing the paired device forgreater lengths of time than the user would tolerate wearing a heavystandalone eyewear device, thereby enabling an artificial realityenvironment to be incorporated more fully into a user's day-to-dayactivities.

The neckband 1005 may be communicatively coupled with the eyewear device1002 and/or to other devices (e.g., wearable device 120). The otherdevices may provide certain functions (e.g., tracking, localizing, depthmapping, processing, storage, etc.) to the AR system 1000. In theembodiment of FIG. 10, the neckband 1005 may include two acousticsensors 1020(I) and 1020(J), which are part of the microphone array (orpotentially form their own microphone subarray). The neckband 1005 mayalso include a controller 1025 (e.g., an instance of the controller 214in FIG. 2A) and a power source 1035.

The acoustic sensors 1020(I) and 1020(J) of the neckband 1005 may beconfigured to detect sound and convert the detected sound into anelectronic format (analog or digital). In the embodiment of FIG. 10, theacoustic sensors 1020(I) and 1020(J) may be positioned on the neckband1005, thereby increasing the distance between neckband acoustic sensors1020(I) and 1020(J) and the other acoustic sensors 1020 positioned onthe eyewear device 1002. In some cases, increasing the distance betweenthe acoustic sensors 1020 of the microphone array may improve theaccuracy of beamforming performed via the microphone array. For example,if a sound is detected by the acoustic sensors 1020(C) and 1020(D) andthe distance between acoustic sensors 1020(C) and 1020(D) is greaterthan, for example, the distance between the acoustic sensors 1020(D) and1020(E), the determined source location of the detected sound may bemore accurate than if the sound had been detected by the acousticsensors 1020(D) and 1020(E).

The controller 1025 of the neckband 1005 may process informationgenerated by the sensors on the neckband 1005 and/or the AR system 1000.For example, the controller 1025 may process information from themicrophone array, which describes sounds detected by the microphonearray. For each detected sound, the controller 1025 may perform adirection of arrival (DOA) estimation to estimate a direction from whichthe detected sound arrived at the microphone array. As the microphonearray detects sounds, the controller 1025 may populate an audio data setwith the information. In embodiments in which the AR system 1000includes an IMU, the controller 1025 may compute all inertial andspatial calculations from the IMU located on the eyewear device 1002.The connector 1030 may convey information between the AR system 1000 andthe neckband 1005 and between the AR system 1000 and the controller1025. The information may be in the form of optical data, electricaldata, wireless data, or any other transmittable data form. Moving theprocessing of information generated by the AR system 1000 to theneckband 1005 may reduce weight and heat in the eyewear device 1002,making it more comfortable to a user.

The power source 1035 in the neckband 1005 may provide power to theeyewear device 1002 and/or to the neckband 1005 (and potentially thewearable device 120, while in other embodiments the wearable device 120includes its own power source). The power source 1035 may include,without limitation, lithium-ion batteries, lithium-polymer batteries,primary lithium batteries, alkaline batteries, or any other form ofpower storage. In some cases, the power source 1035 may be a wired powersource. Including the power source 1035 on the neckband 1005 instead ofon the eyewear device 1002 may help better distribute the weight andheat generated by the power source 1035.

As noted, some artificial reality systems may, instead of blending anartificial reality with actual reality, substantially replace one ormore of a user's sensory perceptions of the real world with a virtualexperience. One example of this type of system is a head-worn displaysystem, such as the VR system 1100 in FIG. 11, which mostly orcompletely covers a user's field of view. The VR system 1100 may includea front rigid body 1102 and a band 1104 shaped to fit around a user'shead. the VR system 1100 may also include output audio transducers1106(A) and 1106(B). Furthermore, while not shown in FIG. 11, the frontrigid body 1102 may include one or more electronic elements, includingone or more electronic displays, one or more IMUs, one or more trackingemitters or detectors, and/or any other suitable device or system forcreating an artificial reality experience. Although not shown, the VRsystem 1100 may include the computer system 130.

Artificial-reality systems may include a variety of types of visualfeedback mechanisms. For example, display devices in the AR system 1000and/or the VR system 1100 may include one or more liquid-crystaldisplays (LCDs), light emitting diode (LED) displays, organic LED (OLED)displays, and/or any other suitable type of display screen.Artificial-reality systems may include a single display screen for botheyes or may provide a display screen for each eye, which may allow foradditional flexibility for varifocal adjustments or for correcting auser's refractive error. Some artificial reality systems also includeoptical subsystems having one or more lenses (e.g., conventional concaveor convex lenses, Fresnel lenses, or adjustable liquid lenses) throughwhich a user may view a display screen.

In addition to or instead of using display screens, some artificialreality systems include one or more projection systems. For example,display devices in the AR system 1000 and/or the VR system 1100 mayinclude micro-LED projectors that project light (e.g., using awaveguide) into display devices, such as clear combiner lenses thatallow ambient light to pass through. The display devices may refract theprojected light toward a user's pupil and may enable a user tosimultaneously view both artificial reality content and the real world.Artificial-reality systems may also be configured with any othersuitable type or form of image projection system.

Artificial-reality systems may also include various types of computervision components and subsystems. For example, the AR system 900, the ARsystem 1000, and/or the VR system 1100 may include one or more opticalsensors such as two-dimensional (2D) or three-dimensional (3D) cameras,time-of-flight depth sensors, single-beam or sweeping laserrangefinders, 3D LiDAR sensors, and/or any other suitable type or formof optical sensor. An artificial reality system may process data fromone or more of these sensors to identify a location of a user, to mapthe real world, to provide a user with context about real-worldsurroundings, and/or to perform a variety of other functions.

Artificial-reality systems may also include one or more input and/oroutput audio transducers. In the examples shown in FIGS. 9 and 11, theoutput audio transducers 908(A), 908(B), 1106(A), and 1106(B) mayinclude voice coil speakers, ribbon speakers, electrostatic speakers,piezoelectric speakers, bone conduction transducers, cartilageconduction transducers, and/or any other suitable type or form of audiotransducer. Similarly, the input audio transducers 910 may includecondenser microphones, dynamic microphones, ribbon microphones, and/orany other type or form of input transducer. In some embodiments, asingle transducer may be used for both audio input and audio output.

The artificial reality systems shown in FIGS. 9-11 may include tactile(i.e., haptic) feedback systems, which may be incorporated intoheadwear, gloves, body suits, handheld controllers, environmentaldevices (e.g., chairs or floormats), and/or any other type of device orsystem, such as the wearable devices 120 discussed herein. Additionally,in some embodiments, the haptic feedback systems may be incorporatedwith the artificial reality systems (e.g., the AR system 900 may includethe haptic device 120 shown in FIG. 1). Haptic feedback systems mayprovide various types of cutaneous feedback, including vibration, force,traction, texture, and/or temperature. Haptic feedback systems may alsoprovide various types of kinesthetic feedback, such as motion andcompliance. Haptic feedback may be implemented using motors,piezoelectric actuators, fluidic systems, and/or a variety of othertypes of feedback mechanisms, as described herein. Haptic feedbacksystems may be implemented independently of other artificial realitydevices, within other artificial reality devices, and/or in conjunctionwith other artificial reality devices.

By providing haptic sensations, audible content, and/or visual content,artificial reality systems may create an entire virtual experience orenhance a user's real-world experience in a variety of contexts andenvironments. For instance, artificial reality systems may assist orextend a user's perception, memory, or cognition within a particularenvironment. Some systems may enhance a user's interactions with otherpeople in the real world or may enable more immersive interactions withother people in a virtual world. Artificial-reality systems may also beused for educational purposes (e.g., for teaching or training inschools, hospitals, government organizations, military organizations, orbusiness enterprises), entertainment purposes (e.g., for playing videogames, listening to music, or watching video content), and/or foraccessibility purposes (e.g., as hearing aids or vision aids). Theembodiments disclosed herein may enable or enhance a user's artificialreality experience in one or more of these contexts and environmentsand/or in other contexts and environments.

Some AR systems may map a user's environment using techniques referredto as “simultaneous location and mapping” (SLAM). SLAM mapping andlocation identifying techniques may involve a variety of hardware andsoftware tools that can create or update a map of an environment whilesimultaneously keeping track of a device's or a user's location and/ororientation within the mapped environment. SLAM may use many differenttypes of sensors to create a map and determine a device's or a user'sposition within the map.

SLAM techniques may, for example, implement optical sensors to determinea device's or a user's location, position, or orientation. Radios,including Wi-Fi, Bluetooth, global positioning system (GPS), cellular orother communication devices may also be used to determine a user'slocation relative to a radio transceiver or group of transceivers (e.g.,a Wi-Fi router or group of GPS satellites). Acoustic sensors such asmicrophone arrays or 2D or 3D sonar sensors may also be used todetermine a user's location within an environment. AR and VR devices(such as the systems 900, 1000, and 1100) may incorporate any or all ofthese types of sensors to perform SLAM operations such as creating andcontinually updating maps of a device's or a user's current environment.In at least some of the embodiments described herein, SLAM datagenerated by these sensors may be referred to as “environmental data”and may indicate a device's or a user's current environment. This datamay be stored in a local or remote data store (e.g., a cloud data store)and may be provided to a user's AR/VR device on demand.

When the user is wearing an AR headset or VR headset in a givenenvironment, the user may be interacting with other users or otherelectronic devices that serve as audio sources. In some cases, it may bedesirable to determine where the audio sources are located relative tothe user and then present the audio sources to the user as if they werecoming from the location of the audio source. The process of determiningwhere the audio sources are located relative to the user may be referredto herein as “localization,” and the process of rendering playback ofthe audio source signal to appear as if it is coming from a specificdirection may be referred to herein as “spatialization.”

Localizing an audio source may be performed in a variety of differentways. In some cases, an AR or VR headset may initiate a Direction ofArrival (“DOA”) analysis to determine the location of a sound source.The DOA analysis may include analyzing the intensity, spectra, and/orarrival time of each sound at the AR/VR device to determine thedirection from which the sound originated. In some cases, the DOAanalysis may include any suitable algorithm for analyzing thesurrounding acoustic environment in which the artificial reality deviceis located.

For example, the DOA analysis may be designed to receive input signalsfrom a microphone and apply digital signal processing algorithms to theinput signals to estimate the direction of arrival. These algorithms mayinclude, for example, delay and sum algorithms where the input signal issampled, and the resulting weighted and delayed versions of the sampledsignal are averaged together to determine a direction of arrival. Aleast mean squared (LMS) algorithm may also be implemented to create anadaptive filter. This adaptive filter may then be used to identifydifferences in signal intensity, for example, or differences in time ofarrival. These differences may then be used to estimate the direction ofarrival. In another embodiment, the DOA may be determined by convertingthe input signals into the frequency domain and selecting specific binswithin the time-frequency (TF) domain to process. Each selected TF binmay be processed to determine whether that bin includes a portion of theaudio spectrum with a direct-path audio signal. Those bins having aportion of the direct-path signal may then be analyzed to identify theangle at which a microphone array received the direct-path audio signal.The determined angle may then be used to identify the direction ofarrival for the received input signal. Other algorithms not listed abovemay also be used alone or in combination with the above algorithms todetermine DOA.

In some embodiments, different users may perceive the source of a soundas coming from slightly different locations. This may be the result ofeach user having a unique head-related transfer function (HRTF), whichmay be dictated by a user's anatomy, including ear canal length and thepositioning of the ear drum. The artificial reality device may providean alignment and orientation guide, which the user may follow tocustomize the sound signal presented to the user based on a personalHRTF. In some embodiments, an AR or VR device may implement one or moremicrophones to listen to sounds within the user's environment. The AR orVR device may use a variety of different array transfer functions (ATFs)(e.g., any of the DOA algorithms identified above) to estimate thedirection of arrival for the sounds. Once the direction of arrival hasbeen determined, the artificial reality device may play back sounds tothe user according to the user's unique HRTF. Accordingly, the DOAestimation generated using an ATF may be used to determine the directionfrom which the sounds are to be played from. The playback sounds may befurther refined based on how that specific user hears sounds accordingto the HRTF.

In addition to or as an alternative to performing a DOA estimation, anartificial reality device may perform localization based on informationreceived from other types of sensors. These sensors may include cameras,infrared radiation (IR) sensors, heat sensors, motion sensors, globalpositioning system (GPS) receivers, or in some cases, sensor that detecta user's eye movements. For example, an artificial reality device mayinclude an eye tracker or gaze detector that determines where a user islooking. Often, a user's eyes will look at the source of a sound, ifonly briefly. Such clues provided by the user's eyes may further aid indetermining the location of a sound source. Other sensors such ascameras, heat sensors, and IR sensors may also indicate the location ofa user, the location of an electronic device, or the location of anothersound source. Any or all of the above methods may be used individuallyor in combination to determine the location of a sound source and mayfurther be used to update the location of a sound source over time.

Some embodiments may implement the determined DOA to generate a morecustomized output audio signal for the user. For instance, an acoustictransfer function may characterize or define how a sound is receivedfrom a given location. More specifically, an acoustic transfer functionmay define the relationship between parameters of a sound at its sourcelocation and the parameters by which the sound signal is detected (e.g.,detected by a microphone array or detected by a user's ear). Anartificial reality device may include one or more acoustic sensors thatdetect sounds within range of the device. A controller of the artificialreality device may estimate a DOA for the detected sounds (e.g., usingany of the methods identified above) and, based on the parameters of thedetected sounds, may generate an acoustic transfer function that isspecific to the location of the device. This customized acoustictransfer function may thus be used to generate a spatialized outputaudio signal where the sound is perceived as coming from a specificlocation.

Once the location of the sound source or sources is known, theartificial reality device may re-render (i.e., spatialize) the soundsignals to sound as if coming from the direction of that sound source.The artificial reality device may apply filters or other digital signalprocessing that alter the intensity, spectra, or arrival time of thesound signal. The digital signal processing may be applied in such a waythat the sound signal is perceived as originating from the determinedlocation. The artificial reality device may amplify or subdue certainfrequencies or change the time that the signal arrives at each ear. Insome cases, the artificial reality device may create an acoustictransfer function that is specific to the location of the device and thedetected direction of arrival of the sound signal. In some embodiments,the artificial reality device may re-render the source signal in astereo device or multi-speaker device (e.g., a surround sound device).In such cases, separate and distinct audio signals may be sent to eachspeaker. Each of these audio signals may be altered according to auser's HRTF and according to measurements of the user's location and thelocation of the sound source to sound as if they are coming from thedetermined location of the sound source. Accordingly, in this manner,the artificial reality device (or speakers associated with the device)may re-render an audio signal to sound as if originating from a specificlocation.

Although some of various drawings illustrate a number of logical stagesin a particular order, stages that are not order dependent may bereordered and other stages may be combined or broken out. While somereordering or other groupings are specifically mentioned, others will beobvious to those of ordinary skill in the art, so the ordering andgroupings presented herein are not an exhaustive list of alternatives.Moreover, it should be recognized that the stages could be implementedin hardware, firmware, software, or any combination thereof.

The foregoing description, for purpose of explanation, has beendescribed with reference to specific embodiments. However, theillustrative discussions above are not intended to be exhaustive or tolimit the scope of the claims to the precise forms disclosed. Manymodifications and variations are possible in view of the aboveteachings. The embodiments were chosen in order to best explain theprinciples underlying the claims and their practical applications, tothereby enable others skilled in the art to best use the embodimentswith various modifications as are suited to the particular usescontemplated.

What is claimed is:
 1. A wearable device comprising: a wearablestructure attachable to a portion of a user's body; a plurality ofbladders, integrated with the wearable structure, configured to expandand contract according to fluid pressure within each bladder; and atleast one conduit configured to transport a fluid from a source to oneor more bladders of the plurality of bladders, wherein the fluid fromthe source increases the fluid pressure within at least the one or morebladders, wherein a respective bladder of the plurality of bladderscomprises: a first bellows coupled to a first surface of the wearablestructure; and a second bellows that: (i) is positioned on top of thefirst bellows and away from the first surface of the wearable structure,(ii) is aligned with the first bellows along an axis that issubstantially perpendicular to the first surface of the wearablestructure, (iii) has an opening adjoining an opening in the firstbellows, creating a passage that fluidically connects the first bellowswith the second bellows, and (iv) is configured to contact the userwearing the wearable structure.
 2. The wearable device of claim 1,wherein: the first bellows includes opposing first and second surfaces,whereby: (i) the first surface defines the first opening and is coupledto the second bellows, and (ii) the second surface defines a thirdopening and is coupled to the wearable structure; and the fluid from theat least one conduit enters the first bellows at the third opening; andthe fluid enters the second bellows, from the first bellows, via thepassage.
 3. The wearable device of claim 1, wherein each bladder of theplurality of bladders delivers a haptic stimulation to the user wearingthe wearable structure when the bladder expands a threshold amount. 4.The wearable device of claim 3, wherein the haptic stimulationexperienced by the user is a vibration stimulation or a pressurestimulation.
 5. The wearable device of claim 3, wherein the hapticstimulation experienced by the user corresponds to media presented tothe user by an artificial-reality system.
 6. The wearable device ofclaim 5, further comprising a communication interface in communicationwith the artificial-reality system, wherein the communication interfacereceives an instruction from the artificial-reality system to create thehaptic stimulation.
 7. The wearable device of claim 5, wherein: theartificial-reality system is a virtual-reality or augmented-realitysystem; and the media presented to the user by the artificial-realitysystem includes visual media displayed on one or more displays of thevirtual-reality or augmented-reality system.
 8. The wearable device ofclaim 1, further comprising one or more sensors, integrated with thewearable structure, configured to monitor a state of a respectivebladder of the plurality of bladders.
 9. The wearable device of claim 8,wherein the one or more sensors are further configured to provide sensordata to a controller based on the monitored state of the respectivebladder.
 10. The wearable device of claim 9, wherein the sensor dataincludes one or more of: (i) measurements of the bladder's expansion,(ii) measurements of the bladder's contraction, and (iii) measurementsof the fluid pressure within the bladder.
 11. The wearable device ofclaim 10, wherein: when the respective bladder is in an inflated state:the one or more sensors are configured to detect depression of therespective bladder; and the sensor data provided to the controllerindicates the depression of the respective bladder.
 12. The wearabledevice of claim 1, wherein the at least one conduit is furtherconfigured to transport the fluid from the source to two or more of theplurality of bladders.
 13. The wearable device of claim 1, furthercomprising one or more additional conduits, each additional conduitbeing configured to transport a fluid from the source to one or moreadditional bladders of the plurality of bladders.
 14. The wearabledevice of claim 13, wherein the source includes a manifold switchablycoupled to the at least one conduit and the one or more additionalconduits.
 15. The wearable device of claim 1, wherein the plurality ofbladders forms a one-dimensional array of bladders along a length of thewearable structure.
 16. The wearable device of claim 1, wherein one ormore bladders of the plurality of bladders are selectively expanded toimprove coupling of the wearable device with the user's body.
 17. Thewearable device of claim 16, further comprising one or more sensors,wherein coupling of the wearable device with the user's body isevaluated according to sensor data generated by the one or more sensors.18. A system comprising: a computing device; a fluid source incommunication with the computing device; a wearable device incommunication with the computing device, comprising: a wearablestructure attachable to a portion of a user's body; a plurality ofbladders, integrated with the wearable structure, configured to expandand contract according to fluid pressure within each bladder; and atleast one conduit configured to transport a fluid from a fluid source toone or more bladders of the plurality of bladders, wherein the fluidfrom the fluid source increases the fluid pressure within the one ormore bladders, wherein a respective bladder of the plurality of bladderscomprises: a first bellows coupled to a first surface of the wearablestructure; and a second bellows that: (i) is positioned on top of thefirst bellows and away from the first surface of the wearable structure,(ii) is aligned with the first bellows along an axis that issubstantially perpendicular to the first surface of the wearablestructure, (iii) has an opening adjoining an opening in the firstbellows, creating a passage that fluidically connects the first bellowswith the second bellows, and (iv) is configured to contact the userwearing the wearable structure.
 19. A method of imparting a hapticstimulation to a user wearing a wearable device, wherein the wearabledevice includes (i) a wearable structure attachable to a portion of theuser's body, (ii) a plurality of bladders, integrated with the wearablestructure, configured to expand and contract according to fluid pressurewithin each bladder, and (iii) at least one conduit configured totransport a fluid from a fluid source to one or more bladders of theplurality of bladders, and a respective bladder of the plurality ofbladders comprises: a first bellows coupled to a first surface of thewearable structure; and a second bellows that: (i) is positioned on topof the first bellows and away from the first surface of the wearablestructure, (ii) is aligned with the first bellows along an axis that issubstantially perpendicular to the first surface of the wearablestructure, (iii) has an opening adjoining an opening in the firstbellows, creating a passage that fluidically connects the first bellowswith the second bellows, and (iv) is configured to contact the userwearing the wearable structure, the method comprising: receiving aninstruction from a computer system to change fluid pressure in one ormore first bladders of the plurality of bladders, wherein theinstruction from the computer system corresponds to media presented tothe user by the computer system; and in response to receiving theinstruction: activating the fluid source to change the fluid pressure inthe one or more first bladders according to the instruction, whereineach of the one or more first bladders imparts a haptic stimulation tothe user wearing the wearable device when each bladder expands athreshold amount.